Hi Andy,
There is one more option you can do which I have used long back. You can declare a parameter as type internal table with NO-DISPLAY option and then pass it using SUBMIT.
(Example: for Report Y_TEST, use PARAMETERS: p_tab1 TYPE <table_type>, where <table_type> is type declaration for the itab.
Then use SUBMIT Y_TEST WITH p_tab1 = itab1[]....
I am not having access to the SAP system now, so please check the syntax. This option should work .
Regards,
Rajesh P Nair.