My first thought is to use a combination of $& (which holds "the string matched by the last successful pattern match") and index.

Update: pos, as btrott points out, is the right answer. My idea won't find multiple instances of your search string per target string (and besides, why re-invent a perfectly round wheel?).

my $R = 'Russ Ethan Jason Eric';
$R =~ /Ethan/;
print index($R, $&), "\n";
$R =~ /Eric/;
print index($R, $&), "\n";
[download]

Prints:
5
17

So, adapting my first code to the better answer, this is how I might look in multiple strings for multiple patterns:

my @R = ('Russ Ethan Jason Eric JAPH', 'JAPH vroom Ozymandias neshura 
+Russ');

for (my $i = 0; $i != @R; $i++){
  while ($R[$i] =~ /Russ|JAPH/g){
    print "Found $& in string $i at: ", pos($R[$i]) - length $&, "\n";
  }
}
[download]

Prints:
Found Russ in string 0 at: 0
Found JAPH in string 0 at: 22
Found JAPH in string 1 at: 0
Found Russ in string 1 at: 30

Russ
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