I don't understand enough of what you are trying to achieve to provide any
code for you.

You say you are trying to eliminate the daily task of copy/paste etc and
have to return the workbook in it's original state without the changes you
make to the Id's. So why is it necessary to change the Id's? What are you
doing with them that makes it necessary to change their format?
Even if it is necessary you can insert the new Id's in a new temporary
column without removing the old column and when finished doing whatever you
have to do with the Id's in the new format then just delete the temporary
column and that leaves the original column of Id's in their original format.

In order to provide any code for you I would need to know exactly what it is
you are trying to achieve with the code.

If you are going to use code then it is probably best placed in another
workbook so that the workbook in question is left without macros unless it
already has macros in it. This eliminates problems created for other people
when opening the workbook if they have not got their security settings
properly set to allow the macros.

If you believe that you can handle some code then open and save a new
workbook to contain the code then try recording a macro of what it is you
want to do in the data workbook. The recorded macro is unlikely to be generic
enough to use on the workbook when the number of rows etc change but if you
post the code you record then maybe I can edit the code to ensure that it is
generic for any number of rows to handle etc.

NOTE: Ensure that you have a backup copy of the workbook before running any
code etc.
--
Regards,

OssieMac