Wycombe Wanderers produced their best performance since their 21-game unbeaten run at the start of the season but were unable to breach a Robins defence that was dogged in its determination to hold out for a 0-0 draw in the second leg of their semi-final.
In former England midfielder Rob Lee and veteran striker Tommy Mooney the Chairboys had the best two players on the pitch; but they were unable to force Cheltenham goalkeeper Shane Higgs into one save of note.
It was a tightly contested first half and the tension was palpable as Wycombe tried to upset their hosts with a high-tempo game, but Cheltenham refused to give ground.
Chances were few and far between in the first 45 minutes with Wycombe having the best of the possession but unable to get men on the end of their plentiful crosses.
Ashley Vincent saw a shot turned around the post by Wycombe goalkeeper Steve Williams - the only on-target shot of the half - but the visiting front two of Mooney and Jermaine Easter always looked capable of conjuring something up.
Easter grazed a diving header wide from a cross by the dangerous Kevin Betsy but Cheltenham finally managed to slow things down leading up to half-time and created a couple more chances of their own.
Midfielder Grant McCann sent a free-kick just over the bar from 30 yards and striker Kayode Odejayi had the ball in the net but the flag was already up for offside.
Wycombe tore into Cheltenham at the start of the second half and of these two former non-league sides, it seemed that the Buckinghamshire club might make their extra six years of Football League experience tell.
Mooney went close with two chances from inside the penalty area and Cheltenham's Gavin Caines was required to make a superb last-ditch tackle on Matt Bloomfield.
At the other end, Cheltenham struggled for attacking options on the break but Steve Guinan spooned high from close range and Brian Wilson drew a fine save from goalkeeper Williams at full stretch.
In the dying seconds of injury-time, Wycombe's Easter turned sharply in the box but flashed a shot inches wide with the game's last chance.
The final will be held at the Millennium Stadium in Cardiff on Sunday May 28.