control Excel VBA macro with a VB 05-designed user interface

[dgr7]

hello,
I have many Excel workbooks that I receive from clients I run various Excel VBA macros on depending on which workbook it is, and I need to automate all of this so that I can run an simple .exe user interface designed in VB 2005 Express Edition where when that interface is run, a small window opens on the destop with a group of buttons, when the user clicks one of the buttons, Excel launches loads the appropriate file and runs an already-existing appropriate Excel macro, then some file maintenance is done, like moving a group of files from one subdirectory to another.
I'm new to VB and don't know where to start to make this happen. Could someone show me how to do this/where to begin?
thanks in advance,
david