As you probably know, when a file is deleted it still exists on the hard drive except for a single number change at the begining - that is until it is overwritten by another file. New files are saved using the first available "empty" space on the hard drive.
I do not know if Excel follows this rule. Interestingly you might have 2 chances because Excel always makes a temporary file which is "deleted" on closing the main one.
The point here is that your file might not be overwritten yet. There is fairly inexpensive recovery software available - but the longer you delay using it the less likely you are to be successful.
If you do proceed with this I am sure that we would all be interested to know how you get on.