  A new family of A_N-type Dunkl operators preserving a polynomial subspace of
finite dimension is constructed. Using a general quadratic combination of these
operators and the usual Dunkl operators, several new families of exactly and
quasi-exactly solvable quantum spin Calogero-Sutherland models are obtained.
These include, in particular, three families of quasi-exactly solvable elliptic
spin Hamiltonians.
