Looks to me like both functions return the index of the "search" string from the beginning of the "within" string. The difference is that InstrRev starts looking at the end of the "within" string. So, Instr("This String has back in it near the front and near the back as well","back") gives 17, whilst InstrRev("This String has back in it near the front and near the back as well","back") gives 56.
I suppose you could subtract the result of the InstrRev function from the length of the "within" string and add 1 to get the length from the end of the string.
eta: (I didn't find the VBA Help for InstrRev helpful at all, did you? No example, no "see also" link. It must have been one of the last things added.)
Thanks guys, and ya i found the vb help confusing, and i don't know why i couldn't figure this one out on my own using trial and error could wrap my head around it. I actually used some guys code i found on the net where he changes the function of instrev but u guys way is much simpler and better!
Only thing is i am using file names with more then one "\" so i have to use instrRev