Maybe you could add a macro to your personal.xls that changes the formatting:
Option Explicit
Sub ChangeFormats()
Selection.NumberFormat = "###-#####-##-###"
'or maybe:
'Selection.NumberFormat = "000-00000-00-000"
End Sub
(Did you really want #'s?)
You could assign it a nice shortcut (ctrl-q???) and then select the range to get
the customformat and hit the shortcut button (or alt-f8 and run it. Or
tools|macro|macros and run it.)
If you're new to macros, you may want to read David McRitchie's intro at:
http://www.mvps.org/dmcritchie/excel/getstarted.htm
===
Personal.xls is a workbook that's stored in your XLStart folder. Each time you
open excel, excel will open this workbook. And you'll have your macro
available.
To create/change the shortcut key:
Tools|macro|macros
select your macro
click on Options
type in your letter (I'd stay away from C/X/V (copy/cut/paste) and other
existing shortcut keys)
and ok your way out and cancel at that last dialog.