I'll email you the sample Word and Excel files I setup. Here is the basic process I used...
1) In Excel, choose your cell to input the variable (Cell A1 in the Sample Excel file.)
2) In Excel, setup the "text" cell that is looking at your variable cell (Cell B1 in the Sample Excel file.) This is where you are going to have to do some manual work. This is the basic equation in Cell B1: =IF($A$1=1,"one",IF($A$1=2,"two",IF($A$1=3,"three","blahblahblah..."

))
Pretty straight-forwrd
3) In Excel, copy the "text" cell.
4) In Word, do Edit\Paste Special. In the Paste Special Dialog Box choose the Paste Link Radio Button, and then choose the method to Paste it As. I chose Formatted Text (RTF) for this example.
5) Tile both Word and Excel on your screen. Watch as you change the "variable" cell in Excel, the "text" cell and the Word Document update live with each change.
6) Word and Excel will retain that link even if you change filenames (I do believe.)
You should be able to get it from there.
Let me know if it doesn't make sense,
Ken Bolen