Vidal spent two seasons with LaLiga giants Barca at Camp Nou before joining Serie A side Inter for a nominal fee in September.
The Chile international has made eight appearances for the Nerazzurri and is expected to start against Madrid in the Group B blockbuster in the Spanish capital.
Should Vidal guide Inter to three points at Estadio Alfredo Di Stefano, he plans to celebrate the victory with supporters of both his old club and new.
"All the matches are decisive for us at this point," he said at Monday's pre-match news conference.
"It will be a good match, important for the table. I will face them as if I were still a Barcelona player.
"I spent two great years at Barcelona, so I hope to be able to celebrate a win with Inter and Barcelona fans."
Vidal is aiming to become the first player to score against Madrid with three separate teams in the Champions League, having previously done so with Serie A powerhouse Juventus and Bundesliga holders Bayern Munich.
The 33-year-old has yet to get off the mark with his first goal for Inter but scored eight times in the league in his final season with Barca, a tally bettered only by Antoine Griezmann (9), Luis Suarez (16) and Lionel Messi (25).
"I used to score many goals but now I have to just give my best and do what the coach tells me," he said. "I always put the team first.
"I'm happy to be playing here and I'll continue doing what the coach asks me to do."
Madrid have won six of their seven home major European matches against Inter, although this is the first time the Spanish side have hosted the fixture since September 1998 – a 2-0 win.