Remote patrol

David Letterman's producers call Regis Philbin "the show saver" because the ageless Philbin can be counted on to barge into the studio on a moment's notice and make Letterman's demanding audience laugh. But now, with the incredible success of "Who Wants to Be a Millionaire," Philbin, its host, can rightly be called "the network saver." If tonight's show (at 7 on Channel 9) goes like the eight previous nights of "Millionaire," ABC will get a huge ratings lift from its "$ 64,000 Question" knock-off. But "Millionaire" signs off next Sunday, and that likely means a trip back to the ratings cellar for ABC a week from tonight for the hour preceding "Monday Night Football." >>>