If you are using the wim you likely got from a mounted source somewhere if you look at that location there should be a sources\sxs in it are cab files for this feature copy to folder and call the command with the sources parameter and point to the location you have the cab files. For me this needs to be in a different spot each time I cannot foresee so I made a batch put the files in the same location as batch and this was the contents of batch DISM /Online /Enable-Feature /FeatureName:NetFx3 /Source:%~dp0 /All
You could also use the offline option to apply it to the wim ahead of time.
