Solving PDE on a curved surface

Hello All,

I'm trying to figure out whether I can use COMSOL to solve PDE on a curved surface. For example, diffusion of species on a 2D curved domain described by:

dC/dt = \Delta_S (C)

Here \Delta_S is the surface Laplace or Laplace-Beltrami operator. For simple surface geometry like a sphere or cylinder I figure I can use coordinate transformation to solve the problem on 2D Cartesian grid. But I'm wondering if there's a way to define the surface operator for arbitrarily shaped surface mesh so that I can solve the equation without doing coordinate transformation. Any leads on this are appreciated. Thanks in advance.

Regards,
Ming