you can use Excel's Find Feature....
edit - find
enter the range name
under options, have it lookin WORKBOOK
click FIND ALL
if none are found then there are no formulas referring to it....
then do the same in VBA to see if there is any references to it in VBA code..
open VBA window - (right click excel icon in top left corner - view code)
Edit - Find
Select "CURRENT PROJECT"
that will find any references to that range name in the VBA code.
of coarse, depending on the names, it may take some logical guesswork on your part to figure out which ones are Named Range References, and which ones are just words meant to stand for something else...