>>162
試してないけど、こんな感じでどう?

case NM_RCLICK:
  GetCursorPos(&(HitTest.pt));
  ScreenToClient(hTabWnd, &(HitTest.pt));
  PopupProc(hTabWnd, TabCtrl_HitTest(hTabWnd, &HitTest));
  break;

BOOL PopupProc(HWND hTabWnd, int iItem)
{
  int nID;

  if (iItem == -1) {
     return FALSE;
  }
  /* 中略 */
  nID = TrackPopupMenu(hSubMenu, TPM_LEFTALIGN | TPM_NONOTIFY | TPM_RETURNCMD, point.x, point.y, 0, NULL, NULL);
  switch (nID) {
     case IDM_DELETE: /* 削除を選択 */
       TabCtrl_DeleteItem(hTabWnd, iItem);
       break;
  }
  return TRUE;
}