You have every right to be confident .
You are a very dogged and determined side and really impressed me the way you stuck with us at the Keepmoat.
There is no reason why you shouldn't go to the new Oldham ground and give them a real game. Its got a nasty slope but if you can play that then you'll stand a real chance. Also its wide - I was amazed how we used the width to such great effect.
Get amongst them, be aggresive - like you did with us , and stick in there and eventually they will crack.
Be aware - make sure you have a good Tomtom or you'll never find the ground and get there early as there is congestion around the car park . Its a nice little set up and for Oldham its their new home so respect it and join in the crack - you can hear every comment and it makes for good fun!!
Good luck Doncaster I'm sure you can do it!