recover HDD from zero fill Help Help Help!

OK so I did not check to see there was a backup of files needed before starting to write zeros to HDD. No way have I ever done this before, always get a backup done before. I have orig. disks to use for full restore but now find I have to see if I can recover files on this drive that is "non bootable" before I can go forward. Help needed. This is not the typical "file recovery" issue. Any help welcome or is this useless? I have exactly one day before it goes back, with or without the needed backups of the My Doc folder...... what can I say.....
Thanks Mika