You mentioned travelling on standby, are you staff? If so then you will have to go to BA staff check in which is located in the Queens Building. There is a walkway from T1 to T2 and is located on the left about halfway along.
You can list on the net, do a quick search on here and you can get find the web address. Alternatively your staff travel should be able to help. I dont have the address to hand otherwise I would post it!
Good luck