#!/usr/bin/perl

use strict; # https://perlmonks.org/?node_id=11136666
use warnings;

my $string = "hello my * name is Rob * and * I am a very nice person *
+ at least * I think * so";

my $x = 30; # or one less, not sure of the exact requirements
my ($part1, $part2) = $string =~ /^(.{0,$x}\*)\s*(.*)/;

print "$_\n" for $part1, $part2;
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Outputs:

hello my * name is Rob * and *
I am a very nice person * at least * I think * so
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