can you post a example / sketch / .3dm file of what you want to achieve ?
If i understand correctly - you can use the surface, extract an Isocurve for each direction (u,v) , divide the Isocurve to get the division points and corresponding parameter per direction, combine both sets auf parameters to get a grid.
this will best work on untrimmend surfaces.
The domain (parameter) of the curve should be the same as for the corresponding u-v direction of the surface
(this might be different if their are trims in a Brep - not sure / not tested)