If speed is your concern, using symbolic methods is usually the wrong approach (especially for large systems or if you need to run something repeatedly). You'll need to calculate your Hessian numerically. There's an excellent utility on the MathWorks FileExchange that can do this for you: the DERIVESTsuite. It includes...

r,mathematical-optimization,quadprog,quadratic-programming

You can do this with the solve.QP function from quadprog. From ?solve.QP, we read that solve.QP solves systems of the form min_b {-d'b + 0.5 b'Db | A'b >= b0}. You are solving a problem of the form min_w {-A'w + pw'Cw | w >= 0, 1'w = 1}. Thus,...