He's confessed to participating in a string of armed robberies in Queens, but the young model who made headlines because of his adolescent affair with a 37-year-old teacher insists there's no reason he can't go from perp-walking to cat-walking. Joshua Walter, now 20, seemed to be in denial when a Post reporter visited him at the Vernon C. Bain jail barge moored off The Bronx, where he's being held in lieu of $550,000 bail. After first telling the reporter, "I got nothing to say to you," he took the tabloid's bait when pressed about his modeling career, asking, "What do you mean? What happened? I still am modeling." Walter, along with three others, faces robbery and weapon-possession charges in connection with the June 14th through July 12th crime spree. And in May, Walter pleaded guilty to disorderly conduct for punching and choking his older lover, former teacher Gina Salamino. As for his career, one modeling industry publicist tells the Post, "I wouldn't count him out, but a lot will depend on how he reacts and what he does now that he's in trouble. America loves a great comeback story." True, but America loves a great thieving thug goes to prison story, too.