I know in Oracle you can use DBA_TAB_COLUMNS (or ALL_TAB_COLUMNS). My SQL Server knowledge is very rusty, but can't you use the INFORMATION_SCHEMA.COLUMNS view?
INFORMAT= specifies the informat to be used when SAS accesses data from a table or view. You can change one permanent informat to another by using the ALTER statement. PROC SQL stores informats in its ...