listview with control child

I have a listview with a child control that sits on a row.

When I left click on the child control, I want it to send the
notification back to the list view so that it selects the row as though
I had just clicked on a normal listview element. So, I handled the
WM_LBUTTONDOWN message in the child control to repost the message to
its parent (the listview) as below:

    LRESULT OnLButtonDown(UINT uMsg,
                          WPARAM wParam,
                          LPARAM lParam,
                          BOOL& /*bHandled*/)
    {
        POINT pt = {GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam)};
        MapWindowPoints(GetParent(), &pt, 1);
        LPARAM lp = MAKEWORD(pt.x, pt.y);
        return GetParent().SendMessage(uMsg, wParam, lp);
    };

But, instead of just selecting that row, the listview treats it as the
x,y coordinate of a selection box that starts in the top-right corner
of the listview and goes to the mouse pointer.

What can I do differently to get the desired behavior?

Thanks,
-PaulH