1) Copy the code between the two ----------------8<-----------------
below and save it to a text file named "CopyApprovalsBetweenGroups.cs"

2) Open a command prompt, and navigate to the directory containing
CopyApprovalsBetweenGroups.cs.

3) Run the following command line (all one one line, you will need to
unwrap the line before running it!):

%WINDIR%\Microsoft.NET\Framework\v1.1.4322\csc.exe
  /r:"%PROGRAMFILES%\Update Services\service\bin
\Microsoft.UpdateServices.Administration.dll" /target:exe
  /out:CopyApprovalsBetweenGroups.exe CopyApprovalsBetweenGroups.cs

This will create a tool called CopyApprovalsBetweenGroups.exe.

(Note if you use Visual Studio to compile the code instead of using the command line above, you need to add a reference to the file microsoft.updateservices.administration.dll in your project, see
bottom of this Web page for more on this:
http://download.microsoft.com/download/7/4/5/7458e392-11de-4543-936c-b5248e344487/readme.htm)


Content of CopyApprovalsBetweenGroups.cs:
--------------------8<----------------------

using System;
using Microsoft.UpdateServices.Administration;

// Usage:
// copyapprovals <name of group to copy from> <name of group to copy to>
class Program
{
  static IComputerTargetGroup FindComputerTargetGroup(
   ComputerTargetGroupCollection groups,
   string name)
  {
   foreach (IComputerTargetGroup group in groups)
   {
    if (group.Name == name)
    {
     return group;
    }
   }

   throw new ApplicationException(string.Format("Computer group {0} not found.", name));
  }

  static void Main(string[] args)
  {
   try
   {
    if (args.Length != 2)
    {
     //System.Windows.Forms.MessageBox.Show("TEST");
     Console.WriteLine("Incorrect number of arguments.");
     Console.WriteLine("usage: copyapprovals <name of group to copy from>" +
      " <name of group to copy to>");
     Console.ReadLine();
     return;
    }

    IUpdateServer server = AdminProxy.GetUpdateServer();
    ComputerTargetGroupCollection groups = server.GetComputerTargetGroups();

    // get IComputerTargetGroup references for the source and destination groups
    IComputerTargetGroup sourceGroup = FindComputerTargetGroup(groups, args[0]);
    IComputerTargetGroup destinationGroup = FindComputerTargetGroup(groups, args[1]);

    Console.WriteLine("Copying update approvals from group {0} to group {1}.", args[0],
     args[1]);

    // loop over all updates, copying approvals from the source group to the destination
    // group as necessary
    UpdateCollection updates = server.GetUpdates();

    foreach (IUpdate update in updates)
    {
     UpdateApprovalCollection sourceApprovals = update.GetUpdateApprovals(sourceGroup);
     UpdateApprovalCollection destinationApprovals =
       update.GetUpdateApprovals(destinationGroup);

     // for simplicity, this program assumes that an update has
     // at most one approval to a given group
     if (sourceApprovals.Count > 1)
     {
      Console.WriteLine(
       "Update {0} had multiple approvals to group {1}; skipping.",
       update.Title,
       sourceGroup.Name);
      continue;
     }
     if (destinationApprovals.Count > 1)
     {
      Console.WriteLine(
       "Update {0} had multiple approvals to group {1}; skipping.",
       update.Title,
       destinationGroup.Name);
      continue;
     }

     IUpdateApproval sourceApproval = null;
     IUpdateApproval destinationApproval = null;

     if (sourceApprovals.Count > 0)
     {
      sourceApproval = sourceApprovals[0];
     }
     if (destinationApprovals.Count > 0)
     {
      destinationApproval = destinationApprovals[0];
     }

     if (sourceApproval == null)
     {
      // the update is not approved to the source group

      if (destinationApproval != null)
      {
       // the update is not approved to the source group, but it is approved
       // to the destination group
       // unapprove the update for the destination group to match the source
       Console.WriteLine(
        "Unapproving update {0} to group {1}.",
        update.Title,
        destinationGroup.Name);
       destinationApproval.Delete();
      }
      else
      {
       // neither the source group nor the destination group have an approval;
       // do nothing
      }
     }
     else
     {
      // the source group has an approval

      if (destinationApproval != null)
      {
       // destination group has an approval; check to see if we need to overwrite it
       if (destinationApproval.Action !=sourceApproval.Action)
       {
        // the approvals are different; overwrite
        Console.WriteLine(
         "Changing approval for update {0} from {1} to {2} for group {3}.",
         update.Title,
         destinationApproval.Action,
         sourceApproval.Action,
         destinationGroup.Name);
        update.Approve(sourceApproval.Action, destinationGroup);
       }
      }
      else
      {
       // destination group does not have an approval; approve
       Console.WriteLine(
        "Approving update {0} for {1} for group {2}.",
        update.Title,
        sourceApproval.Action,
        destinationGroup.Name);
       update.Approve(sourceApproval.Action, destinationGroup);
      }
     }
    }
   }
   catch (Exception e)
   {
    Console.WriteLine(e.Message);
   }
  }
}

--------------------8<----------------------

%WINDIR%\Microsoft.NET\Framework\v2.0.50727\csc.exe /r:"%PROGRAMFILES%\Update Services\service\bin\Microsoft.UpdateServices.Administration.dll" /target:exe /out:CopyApprovalsBetweenGroups.exe CopyApprovalsBetweenGroups.cs