Help Needed - Adjusting Lots of Contributions At Once

Hi everyone! I tried posting about this in the Fundraising forum but haven't had much luck, so thought I would try here as well, as we could really use some help. Does anyone know of a way to adjust many gifts at once, instead of having to do them one by one? We have just learned that the fund/GL we were originally told to use for several hundred recent campaign gifts was incorrect, and now we have to adjust all the gifts. We cannot simply adjust the GL for the fund on the back end, because other gifts have gone into this fund and don't need to be adjusted. In this case, the gifts we need to adjust are identified by Source.

Has anyone encountered a situation like this before?

Thank you!

Katie