Half scale on sheets

[peter.toy]

I want to put a half scale on our drawing sheets and was wondering if anyone with macro/plug-in knowledge has done this before. We currently work with A1 size sheets but often print/pdf A3s before construction issue drawings. I want to show the A1 scale (eg. 1:100) as well as an A3 half scale (eg. 1:200) in the titleblock without having to manually put in text as this can cause inconsistencies.

Can anyone help with this?

[Joe.Ye]

Revit API cannot change the scale value shown in the titleblock. The scale value is decided by the scale of the view port in the sheet. 

[Anonymous]

I am also facing a similar issue would it be possible to create a Shared Parameter which would alway set it self to half of view scale