thanks for the quick reply

the room is 17 x 12..I have no idea why the room did not have its own vent in the first place..the house was built in 1920..makes sense to add a register..how does that happen?? run it through the walls down stairs??? as you can tell I know nothing about it,,,thanks for any more advice I appreciate it so much!!!
also how much do you think it would cost approx to have this done??ball park figure? I live in OHIO