Adding an AND clause to a regex

[d]{1,5}

[d]{1,5}|[^0]{1}

[1-9]d{0,4}

^0*[1-9]d{0,4}$

#!/bin/perl -w

while (<>)
{
    chomp;
    print "OK: $_n" if m/^(?!0+$)d{1,6}$/;
}

0
00
000
0000
00000
000000
0000001
000001
OK: 000001
101
OK: 101
01
OK: 01
00001
OK: 00001
1000
OK: 1000
101
OK: 101

^(?=regex1)(?=regex2)(?=regex3).*

^(?=d{1,5}$)(?=.*?[1-9]).*

var str = user_string;
if ('0' != str && str.matches(/^d{1,5}$/) {
    // code for match
}

var str = user_string;
if (!str.matches(/^0+$/) && str.matches(/^d{1,5}$/) {
    // code for match
}

^([1-9][0-9]{0,4}|[0-9]{,1}[1-9][0-9]{,3}|[0-9]{,2}[1-9][0-9]{,2}|[0-9]{,3}[1-9][0-9]|[0-9]{,4}[1-9])$