You can put validation on the cell so user can enter only what you allow.
But what would you like to occur if user decides to just skip that cell?
Without some VBA it is impossible to "force" a user to enter something in a call
if they choose not to.
And then you must rely on macros being enabled when user opens the workbook.
And a contingency plan in the event they disable macros.
Gord Dibben MS Excel MVP
