Adcom sells a solution.  If that is too expensive, get an Atlas 1056B01 (not a B03) from eBay and we'll tell you how to enter in 5 digit codes for each function.  A Vizio VUR8 (eBay)  will also work.  Make sure that you haven't confused the GTYP-500 and the GTP-500II.  They use different codes, but the two remotes recommended here will send either IR signal.