Its not your handle thats broke its your lock,and it could be many differant reasons,your door could have dropped,one of your shoot/dead/hook bolts might not be working or like you say your latch might be broke,when handle is down in the open possition try and bend door towards its hinges to open it if it dosn't my advice would be to phone around some locksmiths and double glazing repairers in your area and get some quotes,even if you get your door open your going to need a lock so it will lock again.your looking at about £100 for door to be opened and new lock fitted,this includes lock.Make sure you use a locksmith who has experiance with upvc doors as he might charge you more for his time trying to get it to work.good luck on your repair
shaun www.sdwupvcrepair.co.uk
February 2008