At the moment columns P:T all have the same data
validation list applied to them.

Users have been told to start in colum P but this does not
always happen. So I have decided to apply the list only
to column P, Q:T are to be applied with a text lenght
validation (text lenght = 0, and error message telling
them to enter in column P).

This all works fine, what I cannot quite get to work is
the sheet code telling Excel to add the validation list to
column Q when an entry has been made in column P (and so
on until column T has the list)

Hope someone can point me in the right direction.

Gareth