Changing Dim Tables via a program

Hello,

We have a project underway replace two company codes with 1 new company code on R3. This will be accomplished by changing all references to the two company codes at the table level(all tables) in R3 Our R3 org is working closely with SAP on this project. This clearly becomes a problem for BW. We cannot reload all of our objects because of the time required. We are considering taking the same approach on BW--replacing all references in all tables. This includes ods active tables and dim tables. My question is does anyone have any experience doing this and if so are there any important learnings or issues that you can share. This seems doable and seems to be our only alternative to keep the two systems in sync.

Thanks, Carol