I have a form that will call another form and pass an array as a parameter. I am prefixing the @ to pass the whole array. However I cannot get the form to compile. I get the error “Command contains unrecognized phrase/keyword”

This command causes the error
DO FORM OrderSelect WITH -1, @laOrderIDs

This compiles, but only passes the first element’s value
DO FORM OrderSelect WITH -1, laOrderIDs

How do I get the form to compile and pass the whole array?