You can "Get" a value from a spreadsheet and assign it to a value for a !Group!.The groupname that is 'gotten' will equal the name of the cell in the spreadsheet.
<<*Get* = the command
!groupname! = the named cell in the target spreadsheet
spreadsheet.xlsx = the target spreadsheet. If the spreadsheet is in the folder of the source document OR in the assigned Excel folder, you need not 'qualify' -- i.e., add drive and folder information -- the spreadsheet. Otherwise, you must qualify the spreadsheet with full drive and path information.
The Get command is processed 'first', along with other calls in the AskTable, and should be considered as part of the AskTable groupings.
Once 'gotten,', you can use the value now assigned to the !groupname! for any other purpose in the document.