Oracle Database Discussions

I've spent the last three and a half weeks recovering an oracle database (11g 64-bit linux) because of a corrupt block in an online redo log (which I thought was being written to multiple locations). I restored the files, moving some of them around in the process; recovered to the latest possible point; moved files back to their proper location; ran 'alter database open resetlogs'; and one of the datafiles (from a bigfile tablespace) didn't get reset. I checked afterward, and it was marked offline. I do not remember placing the file offline, and cannot find such a statement in my last 300 sqlplus commands, which includes commands well before I renamed this file and the commands surrounding the rename.

Restoring/recovering the database again will take too long, and is a remarkably poor option. Even if the database had opened correctly, the affected tablespace would not have been touched in the two or three minutes the database was open. Is there any way to force oracle to reset the logs again or otherwise fix this one file to mark it with the same date? Only allowing the resetlogs option after an incomplete recovery seems a poor restriction, especially, if files can slip through like this. I'm suspecting there is someway to just fix the checkpoint values for the tablespace, but I don't know where to begin. This particular file is <5% of the database, so if I have to do some sort of backup/restore with just it, that is probably doable.