This forum still seem to have issues after the maintenance and I can't go to your profile. But it doesn't matter. Can you make the correct expression in a textbox?
All I'm saying is that I don't think you can use the approach you're using. You can't reference a column when you want %-totals. Either I would try to use dimensionality() with the expression of the column and include the total (sum(total expression)) but I'm not sure this will work. You can also aggregate the values in the loadscript.
good luck
