Extracting column loads and LL reduction factors use RAM DA

I'm trying to extract gravity column loads and live load reduction factors.  I tried using the interface IGravityLoads1, with the GetStoryGravityReactOnCol method.  But I think I am misunderstanding the input parameter for "lColNum", the column index.  It doesn't seem to work with either the IColumn.lUID nor IColumn.lLabel.  What should this lColNum input be?

Is there a similar example available as the one for beam forces in this thread?

https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/168011/ram-da---trouble-getting-getmemberforces-to-work/481615#481615