I'm sorry but a Beosystem 5000 does only work remote wise with the MCP like you got or the 5000 remote which was special for that system/Beomaster.
If you can locate the very rare IR controller kit in complete condition then you can use the Beolink 1000, Beo4 and so forth.
Keep an eye out on the different ebays as the IR kits do turn up but maybe once a year or something.
I managed to get one but I moved to Beosystem 6500 so never completed the IR kit I got. No I'm not selling it.