The video is the trailer for the French film Cinéman; it contains quotes of and references to many other films. Identify the films quoted in the trailer, using the implied enumeration in the ciphertext as a guide:
ZQQ ZBKS DX THUWC, F CQBWNYQ EO GIEAOQH, ZGT VVPJOGHWRU TX KHVDQ SXCE, GHYBU, PFMPJGYSU, WSWKH ZSVIQC, NUGMPB YPZ OTW RET, CMKB EKUEXL, F GUCWSBXFE TJOSAR, IDN IYFFMKTMX
THE MARK OF ZORRO, A FISTFUL OF DOLLARS, THE ADVENTURES OF ROBIN HOOD, SISSI, CLEOPATRA, BARRY LYNDON, TARZAN THE APE MAN, TAXI DRIVER, A CLOCKWORK ORANGE, THE DUELLISTS
Subtracting this key from the cyphertext, using A=1, etc., produces:
FIL MASH OR TSCEN E WHICHDE PI CTSONEO FYO URTEAMMEMB ER SSTUC KINA NYFIL MTHATFEAT URESI NTHEBO TTOMON EHU NDR EDF ILMS ASLIST E DINTHEINT ERNETM OVI EDATABASE
Fixing the wordbreaks, you get:
FILM A SHORT SCENE WHICH DEPICTS ONE OF YOUR TEAM MEMBERS STUCK IN ANY FILM THAT FEATURES IN THE BOTTOM ONE HUNDRED FILMS AS LISTED IN THE INTERNET MOVIE DATABASE
Once you've done that, you're sent this video. That clip, from Cinéman's credits, is a reference to the film SAFETY LAST!, which is the answer to the puzzle.