My guess is there should be a simpler Custom validation formula than the
following one; but, until someone posts it, this will have to do<g....

=AND(OR(LEN(A1)=3,LEN(A1)=4),ISNUMBER(--LEFT(A1,3)),ISNUMBER(SEARCH(MID(A1,4,1),"abcdefghi jklmnopqrstuvwxyz")))

Rick


"shashidhar" wrote in message
...
HI ALL

please help me in formating a column.
I would like to have it look like 001,001A

i.e
three numbers
or
three numbers and one text

how can this be done in data validation ?