Not exactly what you asked for but the logic pattern for this problem is:
Code:
=IF(AND((B1<(0.2*A1)),(B1>(0.01*A1))),"Condition 1",IF(AND((B1>(0.2*A1)),(B1<(0.75*A1))),"condition 2",IF((B1>(0.75*A1)),"condition 3","no")))
using built in cell formulas, not sure if you can do it in 2k3 with conditional formatting as I am on 2k7 here. You can do it by formula in 2k7 which would require you to break it up into each stage and make a rule for each individual set of conditions
Edit: Never mind my convoluded answer, here is a tutorial:
http://blogs.techrepublic.com.com/msoffice/?p=831