I think if you save the document in 2001 as a file in Word 5.1's file format you *should* be good to go, I might even recommend starting the file in Word 5 and then taking the file to your machine with Word 2001, and seeing if it'll open and save. Then, define formatting and the types of Office features you'll be using with Word 5.1, and try not to stray into the newer functionality in Word'01 that will require a change to the new file format, or that Word 5.1 won't be able to handle. From there, you should be good to go.

That's approximately how I do it when I'm sharing documents between computers with Office 97-2004 and Office 2007/2008.

The biggest thing is whether or not Office01 will open the word5 document and save it.

If it won't, does word5 support rich text format?