A Kris Commons penalty secured a memorable 2-1 win over Spartak Moscow on Wednesday night to pip Benfica to the runners-up spot in Group G - but Lennon is already looking ahead to the knockout stages.
The Northern Irishman: "It is going to be really tough whoever we face as we are going to get one of the top teams in the groups.
"You just don't know what shape teams are going to be in two or three weeks time. But we are there and we're going to enjoy it. We want to progress as far as we can in the competition. Who knows where it might take you?
"The spirit is fantastic, we've got some quality players, they've put everything into the group and they've grown as the campaign has gone on.
"Some of them have enhanced their reputations no end but as a collective they've got great belief in themselves and as I said who knows where it might take them.
"But we look forward to the draw. It is very exciting times for everyone at the club and we have got something we can really get our teeth into in the new year.
"I said at the start - and people laughed at me - when they asked me what my target was and I said I wanted to qualify.
"I think you could see the players progressing here last year. We have got some really talented players we felt could play at European level. This is the premier event and we have had some rough times through it but we are unbeaten at home.
"In the two qualification games we showed great composure and at times when it was backs to the wall we showed great defensive qualities when we needed to which was probably alien to some of the players.
"There were some great individual performances but as a team throughout the games they performed brilliantly."
The Bhoys' qualifying campaign included a momentous 2-1 win over La Liga giants Barcelona - one of the most important nights in the history of Celtic Park.
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