>I want the gridrow highlight when the correct record is found although the focus is still on the combobox

First of all, you may just issue Grid.Refresh and it should work in most cases. Also you can always issue Grid.Setfocus and then Combo.Setfocus, so grid will get line colored and focus returned. It's all simple.
Maybe, I still misunderstand you and you want to have record pointer in grid on old record, but new record (search result) is colored?