Dynamic Variable Creation in SAP B1 Query Generator

/**SELECT FROM [OPCH] T0 **/
DECLARE @DocDateFrom as DateTime
/* WHERE */

Set @DocDateFrom =  /* T0.DocDate */ ‘[%0]’

/**SELECT FROM [OPCH] T0 **/
DECLARE @DocDateTo as DateTime
/* WHERE */

Set @DocDateFrom =  /* T0.DocDate */ ‘[%1]’