"Jake Marx" wrote...
...
Your formula gives the opposite of what the OP was looking for. I think you
meant to write this:

=RIGHT(PartNo,2-ISNUMBER(FIND(MID(PartNo,LEN(PartNo)-1,1),"0123456789")))

Another option is:

=RIGHT(PartNo,1+ISERROR(VALUE(MID(PartNo,LEN(Part No)-1,1))))

Had meant the latter. Definitely a mental lapse on my part. Appologies to OP.