I believe that you'll find Perl's built-in grep command the most useful in this situation...

#!/usr/bin/perl

my $string = "Helloa, this is the string";
my @chars = qw(s,o,m,e,c,h,a,r,s);

if ( grep $string =~ /$_/, @chars ) { print "OK"; }
else { print "Oops"; }
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grep applies the expression(s) in the first argument (either a single expression followed by a comma, or a block { expr1; expr2; .. exprN; } which is not followed by a comma) to each element of the list specified in the second argument, setting $_ respectively. comparable to a foreach loop so the above is more-or-less equivalent to

foreach (@chars) {
if ($string =~ /$_/) { $anymatches++ }
}
if ($anymatches) { print "OK" }
else { print "Oops" }
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hope this helps

p.s. just showing off but you could do this on one line: print grep $string=~/$_/,@chars ? "OK" : "Oops";