format cells not to except dashes

[Guest]

I am trying to format a range of cells not to except dashes (-) ie. when
entering phone numbers 123-123-1234

 

[JE McGimpsey]

Format is a display function only, it doesn't affect how entries are
parsed (I assume you mean "accept").

You can use validation. Select your range (I'll assume that A1 is the
active cell). Choose Data/Validation/Allow:Custom with the formula

=ISERR(FIND("-",A1))

 

[Guest]

Try this:
Using cell A1
Set the numbe format to Special and select Phone Number

Then:
Data>Data Validation
Allow: Custom
Formula: =ISERROR(FIND("-",A1))

If length is an issue:
Use this validation formula instead:
=AND(LEN(A1)=10,ISERROR(FIND("-",A1)))

Does that give you something to work with?

***********
Regards,
Ron