Try

C\S-### works for me.

BTW it won't let me do TS-###, it is the S that is the problem because that
signifies seconds.

--

HTH

RP
(remove nothere from the email address if mailing direct)


"Tim" wrote in message
...
Can anyone tell me why Excel will not let me use the customize option in
formatting cells to "CS-###"? I would like to be able to type in "150"
and
have it automatically come up as "CS-150". I use this function quite
frequently and can not understand why Excel will not allow me to use
"CS-###"
when any other letters work just fine. For example, it will let me do
"TS-###", "SC-###", "XY-###", and so on with no problem at all. But for
whatever reason it will not let me use "CS-###". Is it just my computer
or
my version of Excel? Any input would be greatly appreciated, thank you.