How can i convert video to 2:35 widescreen with just my a1 and software?

Well I suppose you could use an anamorphic lens if you could find one with HD quality. But you would also need an anamorphic lens for your projector then.

The way it's usually done (even by Lucas as I recall) is letterboxing inside the 16:9 frame. Just use your editing software to make a mask in the correct proportion.

What software are you using? Most NLE's will offer a matte that you can use to place over your image.

How do you do it in Vegas?