How to add a prefix to a cell that the user can't delete but they can add data behind the prefix

I want every cell to start with PB22 but want the user to add only the random value behind PB22 without deleting the PB22. Column A PB2200003 PB2200025 PB2201295

Thanks for any info you can provide :)


Solution 1:

Use the CONCAT function. In Col 1 enter PB2, Leave Col 2 for user value. In Col 3 use formula =CONCAT(Col1, Col2). Then Col 3 will display the new value. You can hide Col 1 so users won't be able to change the value.

CONCAT formula