I had the same stick sitting around upstairs so thought I'd look into it for you, basically it wont work.
I used the same process that got my saitek x52 working, but it would seem the PS3 wont recognise the throttle on the sidewinder (as you stated) and on top of this there are not enough buttons to make it feasable, unless you were intending on using a keyboard as well!
Sorry bud, but its either learn to use the pad or get a newer stick I'm afraid.
