DTH told BBC Scotland: "We've got to go out there and play our best game of the season, nothing less will get us through.
"We want silverware this year and to do that we need to take out the top dogs like Leinster."
At the same stage last season Leinster held off a late rally from Glasgow to win 19-15 before losing to Ospreys in the final.
Glasgow lost 22-17 in March's league visit to Dublin and were beaten 6-0 at home when the sides met at Scotstoun in November.
"We've been there a couple of times before," said DTH of the play-off challenge.
"I've been here four seasons and I've seen the Glasgow Warriors take massive strides forward."