Greetings and happy new year to the C4 community! Things change and the years pass by, but FOD and the C4 forum remain standing! :P
I'll start this off by posing a philosophical question-- does there even exist a formula for c4 (that is, a formula waiting to be discovered)?
This is essentially the same as asking: WHY is a correct move correct?
Obviously the primary reason is that a correct move leads to a victory. So now the question becomes, is that the ONLY reason, or are there additional conditions which are always satisfied by the correct move

besides

just leading to a victory?
If leading to a victory is the only reason a move is correct, then there can be no formula. If it's not the only reason, then there probably is a formula.
All positions might not be similar in this regard. Perhaps there is a formula that applies to most positions but not all. This would be useful too. But then we would need a way of identifying which positions are solvable and which are not. (The unsolvable ones could still be "solved" using a brute-force minimax search, which programs already do.)
I haven't thought much about this, so I don't have an opinion on the matter as of yet.
I'm interested to see the work you've done so far, mjolke!
By the way, folks...If we find such a formula, it might constitute a solution to the problem of NP-completeness (I'm not sure though). As you might know, that's one of the Millenium Prize problems. If you solve a Millenium Prize problem you receive 1 million dollars...I mention this as extra motivation for you guys to work on this formula!