First, I assuming that you really don't mean format, because if you do you
can set the format of the cell using Format, Cells before the data is entered.

If instead you want to make sure that the user enters a 2 digit number
divided by a 2 or 3 digit number, etc. Then you will want to use a
Worksheet_Change event and write code to test the entry. Do you want a code
solution? And if so have you specified all the legal entries, for example,
#/### is not legal, nor is ###/####?

--
Thanks,
Shane Devenshire


"Matt" wrote:

How can I ensure that inputs in a particular cell are in one of the
following formats:

# / #
# / ##
## / ##
## / ###
### / ###

Thanks!