If you actually physically deleted the data out of BUT050(which is a bad idea), your only option is to perform a system rollback/restore to a time frame before you deleted the data.
Normally I would say this is a basic question, but I don't think I can ever stress the problems/issues that happen when you update SAP delivered tables directly.
I assume you are friends with your SAP Basis administrators and DBA, if not you probably will need to make sure you have a thank you gift ready for them.
Take care,
Stephen