>Thanks for this. I tried this but it seems that all the columns give a 'not empty' result i.e. it doesn't differentiate between highlighted and not. I'll fiddle more with this one.

It only tells if the property has expression set. Any Dynamic* property is evaluated for each cell (not per column or per row) and result is used but not stored anywhere. IOW, there's no "per column" value because each cell can have it's own dynamic value.