Try this diagram instead
http://www.realoem.com/bmw/showparts...02&hg=64&fg=18 When My heater core went bad I bypassed it, too.
I did this by removing a hose.
To be specific, I removed the one which goes from the heater control valve to the drivers side heater core tube.
Then I ran the hose which you are talking about buying (part no. 64211387010) to the upper port on the heater valve.
So if the heater core was bypassed like mine was, then you have that hose (part no. 64211387010) in your car still.
The one you need is item 4 shown on the link I posted. It does not look like that picture at all, though. It's a very short, bent up hose.