Substitute not working about pyvim HOT 1 OPEN

4.3 Search and replace                  *search-replace*

                            *:pro* *:promptfind*
:promptf[ind] [string]
            Put up a Search dialog.  When [string] is given, it is
            used as the initial search string.
            {only for Win32, Motif and GTK GUI}

                        *:promptr* *:promptrepl*
:promptr[epl] [string]
            Put up a Search/Replace dialog.  When [string] is
            given, it is used as the initial search string.
            {only for Win32, Motif and GTK GUI}