Is there any way to recover a corrupted Excel table?

I had compiled a list of the drugs and their NDC numbers that we needed to aquire in order to update our automatic dispensing system. In other words, a very work intensive task, and a very valuable file.

Long story short, I printed one copy of it (subsequently lost) saved it and shut down the computer for the day. A couple days later I went to retrieve it and it came up reading like those 'wingding' fonts, only the font still read as being 'Ariel'. A local computer nerd says it must've been moved and therefore automatically encrypted by the military security system here (I think its called 'Credant).

Any one have any idea how I can retrieve this info?