Heuristic

Hi All... This is my first post here in the forum.....with lots of expectations from you AI gurus... I have to find a way to solve a six coin game. The rules are: 1. Two players (A & B say)will play the game. 2. A square grid is there with 9 holes at the corners, middle of the sides and the crossing of the diagonals. The square is a fully connected graph. 3. A will place three coins marked with A (will call as A Coin) in any three holes first. Then B will put three B Coins in the rest six holes. They are not supposed to put the coins in a linear fashion. 4. Then each of them in alternate attempts will try to form a straight line with thir coins, like A will try to lineate thre A coins. 5. The game will draw, if it lasts for 32 total attempts (16 for each). I hope, i have expressed the requirements easily. Now, if I opt for a best fast search algo for the statespace graph for this problem, what could be the driving parameters for determining the heuristic function. Awaiting eagerly for responses. Anysort of link that will be helpful to me is welcome. Thanks, Neelraxit