setting lens length x pro1

Hello, just joined and a question already.

I have been enjoying various Leica M and R lenses on my X Pro1, using adapters.
I also have a LEICA D VARIO–ELMARIT 2.8-3.5/14-50mm ASPH and I know I can get an adapter for that too. But, what do I set for the lens length?
I would be most grateful for any advice.

Thank you in advance.