string :str-del ( string $STR , int $START , int $COUNT )
string :str-del ( string $STR , int $START )

Returns a copy of the original string with COUNT characters removed, starting from the START-th character.
If COUNT is omitted, removes all characters from START to the end of the string.

# :str-del example
:set &TXT s'Coding in awful is not much fun.'
:writeln :str-del $TXT i20 i4