Filter by first character not A-Z

[benatom]

How do I write a WHERE clause to filter by all items that have a first
character that is not a member of the alphabet. That is I would like
to find:

001 Undefined
002 Undefined
003 XYX

and not:

A Some thing
B Some thing
C Another thing

 

[Douglas J. Steele]

Try

WHERE MyField NOT LIKE "[a-z]*"

or

WHERE MyField LIKE "[!a-z]*"