Here is the standard relay for our cars at amazon in Germany:
Here is just a relay ( I think this is tighed1 selling relay only)
Zettler AZ970E
I think it is better to repair or replace RCM and fix it correctly. If you start adding more to the mix of electronics already in your car you create additional problems when trouble shooting.
Contact the seller at the ebay Zettler AZ970E link above and check what it will cost to mail you the part. Should save you a good bit of money.