STR$REPLACE

   The Replace a Substring routine copies a source string to a
   destination string, replacing part of the string with another
   string. The substring to be replaced is specified by its starting
   and ending positions.

   Format

     STR$REPLACE  destination-string ,source-string ,start-position

                  ,end-position ,replacement-string
 

Additional information available:

Corresponding_JSB_Entry_Point   Returns         Arguments