Batch file renaming with filters (Pack and Go)

[chancegarrison]

Hi Guys,
I recently had the need to rename a bunch of files and have always used pack-and-go for this type of work, but it left me with something to desire.
Does anyone have a macro that can filter out the renaming function based on file type?

For instance, I need to rename only assembly files and their respective drawings, but there is no way to keep from having the part files and their drawings renamed with the way things are named.