Sorting based on the first column of a defined name range (Unknown)

This is still regarding defined name ranges.

Selection.Sort Key1:=Range("AJ2"), Order1:=xlAscending, Header:=xlNo, _
OrderCustom:=1, MatchCase:=False, Orientation:=xlTopToBottom

Im using the above code to sort. however, I need to base the 'SortKey1' on
the first column of the selected unknown defined name range.

Without knowing that AJ2 is the first column of the define name range that
is selected (which was selected using "Range(Range("A2").Value).Select"
, I need to sort based on the first
column of the selected range.

Can this be done?

Thanks again,
Paul