finding/extracting the shear centre of a Beam

All,

I am trying to write a macro to automatically apply an offset to a built up member. I need to align a variety of UPT general sections to a common Top of Steel.

To do this I need to know the shear centre (or centroid as the beams are symmetric)  of the beams in question as that is where Is there anyway to extract this from STAAD

The program must know the values as all beams are automatically positioned relative to shear centre 

The OpenSTAAD get properties does not seem to report

Thanks

Donald