Been there, seen it, done it is the seventh level of the Tricky difficulty in Lemmings.
This level is called The ascending pillar scenario on the Genesis/Mega drive version, identical to the taxing level of the same map, The ascending pillar scenario (which is also present Genesis/Mega drive).
You're gonna have to utilize Builders mainly. First, use a Blocker near the water to prevent drowning. Then order a Lemming to start building the staircase to the left. You could use another Blocker if you desire, however, it is better to use a Digger or a Miner to smash the staircase somewhere at the bottom or middle, so the other Lemmings won't interfere whilst the Builder prepares the course. Since there are plenty of pillars, you'll use up at least 10 Builder skills. At the last pillar, give Digger ability to your Lemming, and allow him to dig into the pillar about half distance. After this, give him Basher or Miner ability, so he'll chew thru the pillar to the left. Keep your eyes peeled, and once your Lemming has penetrated the pillar, give him a Builder ability, so he'll be able to construct a safe passage across the water into the exit. Once done, repair the wrecked staircase near the start, so all your Lemmings could walk to the exit. Blow up the Blocker to finish the level.