Parameters are accessed with C4DAtom::GetParameter()/ C4DAtom::SetParameter(). See Parameter IDs.
Parameter: Polygon Type
ID_REMESH_POLYGONTYPEParameter: Polygon Target Mode
ID_REMESH_POLYGONTARGET_MODEParameter: Mesh Density
ID_REMESH_POLYGONSCALEParameter: Polygon Count
ID_REMESH_POLYGONTARGETParameter: Keep Outline
ID_REMESH_KEEPOUTLINEParameter: Keep Creases
ID_REMESH_CREASESParameter: Edge Angle
ID_REMESH_EDGEANGLEParameter: Smooth Iterations
ID_REMESH_SMOOTHITERATIONSParameter: Only Quadrangles
ID_REMESH_QUADONLYParameter: Flow Splines
ID_REMESH_GUIDE_SPLINES