If you use #DEFINE it works.
>It could be nice way to use include file with _parts_ of strings. However, it does not works in following example:
>
>#DECLARE MyTableName Invoices
>
>...
>=messagebox([Table MyTableName does not exists!])
>...
>=messagebox([Table MyTableName processed.])
>
>Message boxes show 'MyTableName' instead of 'Invoices'.
>
Insanity: Doing the same thing over and over and expecting different results.