Creating scenarios and same direction passing

I've just started playing with making my own scenario. I'm using the Riviera Line going south from Exeter.

I've made it so that I'm driving a stopping service followed by a non-stopping express. When I get to Dawlish Warren I enter the station loop and the express catches up to the red signal behind me as I stop. When stopped, both main line and loop signals ahead of me show red.

I've set my service to be two parted, ending at Dawlish Warren and a second part to complete my journey to Plymouth.

Is there a way I can force priority to the main line? My aim is to have the express pass while I am in the station.