Applying conditional formatting to field parameter columns

Hi PowerBi peops!

I am struggling to figure this one out. I have a DAX formula which allows me to conditionally format the background color of the columns (alternating color by session_ID). I would like to apply this DAX formual to the additional columns, but these columns are within a field parameter called "Select additional column". Since field parameters don't have a conditional formatting option, how am I suppose to do this? Thanks in advance!