I am using Excel 2000

I use a reference which is set up as 2 alpha, 6 numerics and one alpha
(aannnnnna). It is the National Insurance (Social Security) Number given to
everyone at age 16.

I wanted to use a format to ensure that the item was being entered properly
and I would also like it to be displayed as 'aa nn nn nn a' (the normal
method of notation).

I tried setting up custom formats '@@ ## ## ## @' and '@@ @@ @@ @@ @'
neither of which worked, nor could I find any formats of this type.

Is there a way of setting up a custom format that will a format of this type.

May I thank you in advance for your help.

Sean Bishop