separate the Text from the first two Characters of the post codes

[Sasi]

How do I separate the Text from the first two Characters of the post code
i.e. for SW1 1KP, answer should be SW and for S20 1PU answer should be S.
Help in access or sql

 

[Ken Snell [MVP]]

Alphas: Left([PostCode], 2 + IsNumeric(Mid([PostCode], 2, 1)))