Curtain mullion parameters and formulas

[Dimitri Harvalias]

Is it possible to use a formula to define the 'offset' in the curtain mullion paramaters? e.g. =Thickness/2 I am trying to create a glazed elevator enclosure and want to have the interior face of the curtain wall aligned with the inside of the elevator shaft. If the offset can be automatically 1/2 the depth of the mullion then I don't have to bother changing each time the curtain wall section is revised.
I know that only instance parameters can use formulas, but can the parameters for curtain walls be modified?
Any help appreciated.
Thanks
Dimitri

[sbrown]

I just specify an offset for the mullion and the glazing panels, I place the curtain wall ref. line where ever I want to dimension to. then offset the mul and panels from there.