So I can tell you this is no small task. Making the Campy H11 levers and Magura M2, or M4/M6 calipers work will cost you time and $$$. I've spent a least $300 wholesale buying stuff to make it work and I'm still not done. I work PT at a high end bike shop. I have the ability to order parts, and get expert help from my friends who work at the shop. They work on hydraulic brakes a lot, and I don't do repairs anymore so the guys at the shop are helping me. Banjo fitting are on the levers and you need banjo fittings at the caliper to use the M4/M6 calipers. Well this is not so simple as the you know because this is not how these things work. Banjo on one end means NO banjo on the other. Adding a barb fitting does not work either as the hydro cable doesn't expand. The Campy hydro cables are thin. I'll add more when I finally get it working properly.
I actually found this to be pretty easy. I had a frame that I bought, a Titanium Seven, with post mount in the rear triangle, so not easy to change. The Enve fork was under recall, so I swapped it for a flat mount fork. I did a lot of research and came up with the same solution many here have suggested - use a Magura MT8 caliper with the Campy H11 system. Long story short, that's what I did. I'm running the H11 EPS system, Campy front caliper, Magura rear caliper - all is good. Lever feel is the same, modulation is the same, stock pads front and rear.
The key is to get a Magura compatible banjo fitting with a barb on it that uses an olive for compression, and a compression nut. Use the stock Magura mounting bolt. I cut the Campy brake line to the right length, slid the nut and olive over the tubing, pushed the barb ended banjo bolt in, tightened the nut on the banjo, fitted the two o-rings into the banjo, and then fitted the banjo to the caliper. Bled the system with a magura bleeder syringe on the Magura end, and the Campy bleeder on the lever end. Straightforward. No leads. No fade. I'm not an expert on Magura products - I don't use them on my mountain bikes - but I am told that the Magura calipers are similar or identical from the 2 to 8 series. I've only run this for a few weeks, so I don't have any long term results.
I bought my MT8 used on eBay for $40. I have $10 in fittings. I'm keeping my Campy H11 rear caliper for a future build. So, it's a cheap and easy solution in the end.
I don't warranty any of this information, I'm not a bike shop, just an engineer who has been tinkering with bikes and Ducatis for 40 years...