United face neighbours St Johnstone at Celtic Park with the 22-year-old going into the showpiece on the back of signing a new two-year deal at the club.
Back-up goalkeeper Marc McCallum also signed a new contract which will keep the 21-year-old at Tannadice until May 2016.
Dow is also keen to sample European football next season, and winning this weekend will give him an opportunity to fulfil that ambition.
"I signed a new deal and it came the same week as the Scottish Cup final so it could cap a brilliant week," he said.
"Missing out on second and third in the league, it is a big opportunity to win a cup and the bonus on top of that is to get into Europe where we wanted to be.
"It is a big double, winning the cup and getting into Europe. I have been playing more in the last six months, the gaffer has given me a run of games.
"I like the style of football we play, I am happy, I am a local boy, so everything was in place to sign. Some of the stuff we have played this year has been outstanding and to be involved in those games and performances - long may it continue.
"Hopefully this team stays together. We have a really exciting team and we could go on to big things.
"It is good playing attractive football and finishing in Europe but trophies are a hard thing to come by so if there is an opportunity to get one you are going to do everything possible to get one."
Watch Dundee United take on St Johnstone live from Celtic Park from 2.30pm this Saturday on Sky Sports 1