cd cable / lead....

Hi landy lovers.. advice on a cd cable/lead/bus.. I got a alpine head unit of ebay and want to marry it up with a alpine cd changer out of me xj8 ... the changer has a round male plug(7pin) and the new head unit has a oblong female... both alpine.. but i canny find a lead on ebay to suit?? can this to be done?? if so where do i go?? is it just a case of gettin a lead from a top model p38 .. mine is a 1998 dse...any help would be great.. many thanks stuart