Here's an approach. File ask_to_replace_1.pl: 

use warnings;
use strict;


my $string = 'Three, Four, One, Two, xFive9, six, Seven';

my $number = qr{ \b [[:upper:]] [[:lower:]]+ \b }xms;

print qq{string is now '$string' \n};

my $ordinal = 0;

$string =~ s{ ($number) }
            { ask_replace(++$ordinal, $-[1], $1) }xmsge;

print qq{new string is '$string' \n};
print qq{done! \n};


sub ask_replace {

    my ($ordinal,
        $offset,
        $string,
        ) = @_;

    my $yes = qr{ (?i) y (?: e (?: s)? )?  }xmso;
    my $ok  = qr{ (?i) o (?:          k)?  }xmso;
    my $accept = qr{ \A (?: $yes | $ok) \Z }xmso;

    print qq{sub-string $ordinal at offset $offset is '$string' \n};

    print qq{is this correct? };
    my $answer = <stdin>;
    return $string if $answer =~ $accept;

    print qq{no: enter new string: };
    chomp(my $replace = <stdin>);
    return $replace;

    }

[download]

Output: 

c:\@Work\Perl\monks\Keystone>perl ask_to_replace_1.pl
string is now 'Three, Four, One, Two, xFive9, six, Seven'
sub-string 1 at offset 0 is 'Three'
is this correct? n
no: enter new string: Uno
sub-string 2 at offset 7 is 'Four'
is this correct? No
no: enter new string: Dos
sub-string 3 at offset 13 is 'One'
is this correct? y
sub-string 4 at offset 18 is 'Two'
is this correct? x
no: enter new string: Tres
sub-string 5 at offset 36 is 'Seven'
is this correct? n
no: enter new string: se7en
new string is 'Uno, Dos, One, Tres, xFive9, six, se7en'
done!

[download]

In reply to Re: RegExp substitution by AnomalousMonk
in thread RegExp substitution by Keystone

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