Here's the first page of the sheet music fo Ben Xuan:

I don't know how much music notation you know, but I'm just going to assume you know the basics.
To use the Composer, download the user guide for this phone here
http://downloads.nokiausa.com/userguides/1100.PDF(right click, save as)
It's on p. 25
It's gonna be basically press 1 for middle C, 2 for D, 3 for E, etc. For a sharp, you have to press #. There isn't a key specifically for flats, but a B flat is the same as an A sharp; so you would press the key corresponding to A, which is 6, and make it a sharp by pressing #.
So, without further ado, here are the key sequences to type in for Ben Xuan:
2 5 4 8 5 2 9 6 # 8 1 * 2 9 9 1 8 8 2 6 # * * 9 6 8 6 # 5 9 9 4 8 8 5 4 8 2 9 9 1 8 8 2 9 4 8 5 6 8 8
It's pretty tedious to translate a song by using 9 buttons on your phone, and...one mistake would screw up the whole song. So the above is still incomplete, but it should for now. Hy also asked me to make one for her, so what I'm gonna do is program a little applet to translate the notes for me. This might take about a week or more since I don't have any free time during the day.
Ooh, my lucky day. I don't have to make a program after all, there already is one:
http://www.ringtone-composer.com/Edit again:
ack, you have to pay for them. If I can't find a free one, I'll try to make a basic one. Stay tuned.