How do I add CB_SETITEMDATA to a comboBox with wstring variable as the LPARAM?

Also, is it correct and OK to put the declaration of the wstring in side of this loop?  Currently, with this code I'm getting the following error message from the compiler.
Error      1      error C2440: 'initializing' : cannot convert from 'std::wstring *' to 'std::basic_string<_Elem,_Traits,_Ax>'      c:\Projects\UnityExtProperty\CUserPage.Cpp      884



//while (loop condition is true)

                                    // Add the context cn attribute
                                    std::wstring wsGroup = new wstring;
                                    wsGroup = (colSearchColumnDN.pADsValues->CaseIgnoreString);
                                    SendMessage(hwndPrimGroup,CB_SETITEMDATA, index, (LPARAM)T2CW(wsGroup.c_str()));
                                    primaryGroups.push_back(wsGroup);
                                    padsSearchContainer->FreeColumn( &colSearchColumnDN );

//end while loop