Metric Part Dimensions in Parametric Cell Studio

I am assuming that to get the system to acces part dimensions in Parametric Cell Studio  in metric format rather than imperial format I have to change the access path from 

C:\ProgramData\Bentley\MicroStation V8i (SELECTseries)\WorkSpace\TriForma\tf_imperial

to

C:\ProgramData\Bentley\MicroStation V8i (SELECTseries)\WorkSpace\TriForma\tf_si

Which configuration varible controls this or is there another approach?