Well you're in luck, because you're almost done! First you have to link the table. To do this go to the Management Portal: System Explorer->SQL. Then go to Actions->Linked Table Wizard. Choose the SQL Gateway connection from the drop down and choose your table. Go through the couple of screens where you can normally accept the defaults.
Once you link a table, then you can interact with it as if it were local! That is, you can pretend the table is not linked, and use the SQL and/or Object access you're used to in Caché, and access the data in the remote tables. If you are having ANY trouble with this, contact the WRC and one of us will be happy to walk you through the procedure.