It takes a little extra work, but it is certainly do-able...

#!/usr/bin/perl -w
use strict;

my $find = 'proof(\S+)';
my $rpl  = '"read$1"';
my $text = 'proofing is proof it needed to be proofed';

if ($text =~ s/$find/$rpl/ee) {
    print "1st replacement made:\n\t$text\n";
}
[download]

The nested quotes are needed in defining $rpl because without the inner double-quotes, the second /e fails. Another way to do that bit (and this may help in understanding) would be: my $rpl  = '"read" . $1'; You have to get both the quoting and the /ee right for the thing to work as intended.

HTH

------------------------------------------------------------
"Perl is a mess and that's good because the
problem space is also a mess." - Larry Wall