1. Export your map in the WorldBuilder 2. Start COH2, Publish your map to the WorkShop, exit COH2 3. Locate your exported .sga file in my games\company of heroes 2\mods\scenarios and make a copy of it to my games\company of heroes 2\mods\scenarios\subscriptions 4. Goto your recently published map WorkShop page and select "Share".
Copy the 9-digit number from the end of the url. Example result: http://steamcommunity.com/sharedfiles/filedetails/?id=279533345
5. Rename the copy of your map to #########.sga where ######### is the 9-digit number you just copied. 6. Launch COH2. You will now have 2 identical maps available in the map browser. Usually the one in the bottom of the list is the one from the WorkShop. You can just try in the lobby which map triggers the download icon for other players.
Thank you for the faster, easier way. This is a particularly amusing oversight that I hope gets patched quickly. In the meantime, you've saved me many a tear, Janne.