Lock rows based on value in another column

Hi All

I need any assistance to create a macro (Excel 2003) to lock all the level 1 & 2 rows in the attached worksheet, this is a cutdown highly modified example of a model I have.
I have a macro to populate the sheet on a monthly basis at the same time I would like the macro to look for all cells in Column A that have the value 1 or 2 and then lock the whole row, also if it does not have those values in it, it should keep it unlocked.

I have googled and searched this Forum to no avail if I have missed it please can you just point me in the right direction.

Regards,

Added:
Instead of using a Macro I used Data Validation, Custom and used the Formula "=$A2<>2", remembering to de-select "ignore blank" checkbox.

Why would you want to do this?