How to Change DisplayDimension's ExtensionLine offset or direction (in SLDDRW)

Hi All SW API experts,

I am using SW 2016.

I have a drawing view with a simple dimension like:-

And, via API, I want to convert this to :-

I am not sure if this is extension line offset or direction.

I am currently using API "DisplayDimension.GetDimension2(0).ExtensionLineDirection" method to get the direction. But that API giving a vector(0,0,0). Also that is NOT working for setting different value.

I have also used different APIs related API IDisplayDimension.GetWitnessLineGap​, but none seem to work.

Kindly guide me.

Thanks in advance.

SolidworksApi/macros