Drag a window by its client area?

[bops]

case WM_NCHITTEST:
        {
             UINT uHitTest;
             uHitTest = DefWindowProc(hwnd, WM_NCHITTEST, wParam, lParam);
                 if(uHitTest == HTCLIENT)
                     return HTCAPTION;
                 else
                     return uHitTest;
        }
        break;

I came across this code that can be used to drag a window by its client area, which is what I need. However using this code stopped my WM_RBUTTONDOWN message from functioning correctly, which meant I could not handle right clicks. Are there any other ways of doing this? or could the above code be modified so that it does not affect any other window messages.

Thanks.