catgets catHandle setnum msgnum defaultstr
              Retrieve   a   message   form  a  message  catalog.
              CatHandle should be a Tcl  message  catalog  handle
              that  was  returned by catopen.  Setnum is the mes-
              sage set number, and msgnum is the message  number.
              If  the message catalog was not opened, or the mes-
              sage set or message number cannot  be  found,  then
              the default string, defaultstr, is returned.

              This command is provided by Extended Tcl.