al_ustr_replace_range - Allegro 5 API

       Replace the part of us1 in the byte interval [start_pos1, end_pos1) with the contents of us2.  start_pos1
       cannot be less than 0.  If start_pos1 is past the end of us1 then the space between the end of the string
       and start_pos1 will be padded with NUL ('\0') bytes.

       Use al_ustr_offset(3alleg5) to find the byte offsets.

       Returns true on success, false on error.

       al_ustr_replace_range - Allegro 5 API

al_ustr_set_chr(3alleg5)

Allegro reference manual                                                          al_ustr_replace_range(3alleg5)

              #include <allegro5/allegro.h>

              bool al_ustr_replace_range(ALLEGRO_USTR *us1, int start_pos1, int end_pos1,
                 const ALLEGRO_USTR *us2)