22616 Help with .rtf format

Hello, We have a simple .rtf (rich text file) document, that we have fomatted. And now we have this problem: we want the margins (upper, lower, left and right margins) of one page (out of a 30 page document) to be different from the other 29 pages. So for instane page 1,2,3,4 hav certain margings, and then page 5 has different margins, and then page 6,7,8,9, et cetera have the same margings again. But we don't know how to do that. So this is the project: if you know how to do this, you explain it to us and we'll pay you. Friendly Greetings, Jaap