Sometimes searched expression can be more complex like:
855965-401 revJ2, 855965-403 revJ2, 855965-405 revJ2

Off the top of my head and untested, you may be able to do this more easily using getwordnum() and getwordcount(). Code similar to this if the revision expression is always at the end of the string you are searching:

lcRevision = GETWORDNUM( lcSearchString, GETWORDCOUNT( lcSearchString ), [ ] )