Ok, now that I have had the night to think about it I do not believe that the logic of my code will work for my situation.

This is actually an attempt to rename a family of Creo/Parametric 3D CAD models/assemblies/drawings. If anyone is familiar with the way Creo (previously Pro/Engineer) works, inside the assembly and drawing files is the potential for thousands of references to other part (.prt) and assembly (.asm) files. So if you need to change the file name of a part or assembly it is not as simple as renaming the file, you have to update the references in the file as well. This is very labor intensive using the Creo software itselft as you have to have all the files open at the sametime and Creo limits you to having 15 items open at one time.

I need a way to take a set of characters "ABC-123" and go thru each folder and subfolder and rename any files and update any references in those files to the new number "XYZ-789".
Please let me know if this doesn't make any sense.
Again any help is greatly appreciated.