Gregorio Manzano was in confident mood after the 0-4 victory against Vitoria Guimaraes seeing the red and whites qualify for the group stage of European competition. 'We enter the UEFA Europa League in a big way,' said the Atletico coach after accounting for wins in all games played in previous rounds with a total of 10 goals for and 1 against.   Celtic, European champions and runner-up in 67 & 70, return to the stage where they ended their last big dream in this competition in 74, as Udinese and Rennes play for the rest of the points in the group in Italy.   In addition to the atmosphere, Celtic will have to play well against the statistics. Apart from the Cup semi-final of Europe of 74, Atletico also won the other game preceding the first round of the 1985/86 Cup Winners Cup (1-1 in Madrid and 1-2 in Glasgow). A couple of bits of additional data for the Spanish team for optimism, a Scottish rival has never won at the Calderon. Tonight is the time to strengthen these numbers.