Find rows starting with non-alpha sign

Having this code:

开发者_JS百科$val_sql = "";
$stm = $dbh->prepare("SELECT * FROM table WHERE column REGEXP ?");
$stm->bindValue(1, $val_sql, PDO::PARAM_STR);
$stm->execute();

How do I find rows NOT starting with alpha signs?

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you can try to:

$val_sql = "^[^a-z]";