Here is the code snippet...

Sub DesignateStartingCell()
MsgBox "Select the starting cell for the first column"
Call GenerateNames("START_SPEC", "SPECS")

End Sub

The GenerateNames("START_SPEC", "SPECS"), is going to the generate a
NAMED RANGE at the selected cell. The name is START_SPEC and the sheet
name is SPECS.

May be I should use a msg like "Have you selected appropriate starting
Cell?" If the user clicks on YES, the code runs and if the user clicks
on NO the exit without calling GenerateNames("START_SPEC", "SPECS")...