The URI module does not help you because orsr.sk is not conforming to the standard RFC 3986 which clearly states to use UTF-8 encoding, not Windows-1250. So let's piece together the URI manually. 

use utf8;
use URI::Escape qw(uri_escape);
use Encode qw(encode);

for my $name (
    'Ján Slota',
    'Peter Kažimír',
    'Alojz Hlina',
    'František Mikloško',
    'Ján Počiatek',
) {
    my ($pr, $meno) = split ' ', $name;
    printf "http://www.orsr.sk/hladaj_osoba.asp?PR=%s&MENO=%s&SID=0&R=on\n",
        map { uri_escape encode('Windows-1250', $_) } $meno, $pr;
}

__END__
http://www.orsr.sk/hladaj_osoba.asp?PR=Slota&MENO=J%E1n&SID=0&R=on
http://www.orsr.sk/hladaj_osoba.asp?PR=Ka%9Eim%EDr&MENO=Peter&SID=0&R=on
http://www.orsr.sk/hladaj_osoba.asp?PR=Hlina&MENO=Alojz&SID=0&R=on
http://www.orsr.sk/hladaj_osoba.asp?PR=Miklo%9Ako&MENO=Franti%9Aek&SID=0&R=on
http://www.orsr.sk/hladaj_osoba.asp?PR=Po%3Fiatek&MENO=J%E1n&SID=0&R=on
edit: Windows-1250, not -1252. choroba++

In reply to Re: Percent encoding of URIs with UTF-8 characters by daxim
in thread Percent encoding of URIs with UTF-8 characters by reisinge

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