#! perl -slw
use strict;

my $data = do{ local $/; <DATA> };
my $start = '(';
my $stop = ')';
$data =~ s[((?:^|\Q$stop\E).+?(?=\Q$start\E|$))]{
    my $toModify = $1;
    $toModify = uc $toModify;
    $toModify;
}seg;

print $data;

__DATA__
The text from your OP goes here.