This was called "Kampfgruppen Commander" and was in the works by Christian Koppmeyer (TD of German Grenadier tournament).
Years back it was in playtesting stage using various geomorphic boards in a mixture of especially designed as well as existing scenarios for a France 1940 campaign. Each side could buy a number of "core" units that would stay with you throughout the campain (including such things as taking losses, being reinforced/repaired, gaining experience etc.) and other units that could be bought just for a single scenario. This process was using a number of cards for the varying units.
I think the difficulty in the project lay in the fact, that the campaign proved quite lengthy but I do not know the details. I know that the mechanics of "Kampfgruppen Commander" has seen a major edition of its physics, but again can give no details.
As far as I know, "Kampfgruppen Commander" is not dead, but it is surely not on priority for Christian either. If you are interested in further information, you could contact Christian via the Grenadier homepage:
http://www.asl-grenadier.de/
All the best
von Marwitz