dirichlet BC in the free surface model

Hello people,
I am using the free surface model available in Palabos and now I wonder how I could apply a dirichlet BC for the velocity.
The following should still work, right?

OnLatticeBoundaryCondition3D<T,DESCRIPTOR>* boundaryCondition = createLocalBoundaryCondition3D<T,DESCRIPTOR>();
boundaryCondition->addVelocityBoundary1P( Box3D(…), lattice, boundary::freeslip );

Thank you for your kind reply!!!