Can you give us more information? Do you know how to do an ABC version of the tune, or can you do a midi file, or point to a file of it on the web somewhere, or can you give us a copy of the sheet music either scanned in as a graphics file, or typed in to a music notation software programme such as Noteworthy - a programme available as a free demo download?
As a last resort, could you telephone someone here and sing it to them over the phone, or join the Mudcat chat session and sing it?
You'd have to become a Mudcat member to do the last one, but membership is free, no strings attached, and the people here are not only very helpful, but one of the friendliest bunches of people I have ever met on the Internet.
We'll help if we can but there must be thousands, or hundreds of thousands of waltzes in existence, and we need to have some more specific information.