use strict;
use warnings;

my $data = 'func1(x, "%f", "hello")';

$data =~ s/ ( func1 \( x, \s \" ) % (.) "/$1text %$2 and %$2..."/ix;

print ">$data<\n";

##</code><code>##

19:23 >perl 1694_SoPW.pl
>func1(x, "text %f and %f...", "hello")<

19:23 >