I am using a combo box to fill in data in a spreadsheet.

One part of the data is the date. I have set the required
cells to the following format dd/mm/yy, but when a date is
input via the combo box sometimes the month and date are
swapped around, eg 11/05/03 (11th May 03) is interpretted
as 05/11/03 (5th Nov 03). other dates eg 23/06/03 are
interpretted correctly.

My Control Panel setting are set for the UK.

Also, I want to only allow input in this box as a date
format. if it is not recognised as a date eg 56/85/09 it
will ask for another input.

Any ideas?