Why not use a regular expression? If you've never used these perhaps a visit to either the MySQL website (http://www.mysql.com) or the PHP website (http://www.php.net) is needed? In short, try this;
SELECT [field] FROM [table] WHERE [field2] REGEXP("[0-9]");
Says select [field] from [table] where [field2] starts with a number, the ^ means beginning of the line, [0-9] selects any number from 0 to 9 - providing the search you need.
HTH
Matt