When using
LIKE[
^] is the situation you describe you need to use the '%' wildcard.
If a string should start with a particular pattern (in your case "#STA") add the wildcard '%' to the end of the pattern. The wildcard '%' stands for any string of zero or more characters.
So use
IF @id LIKE "#STA%"
and any string that begins with "#STA" would mean
"DO SOMETHING"
is executed.