If you have the numbers 0x000000, 0x010000, 0x020000 and 0x030000, then you can increment them using addition ($array[1] += 1;) or using the pre or postincrement operator (++$array[1]; or $array[1]++;).
my @nums = (
0x000000,
0x010000,
0x020000,
0x030000,
);
++$nums[1];
printf("0x%05X\n", $nums[1]);
If you have the strings 0x000000, 0x010000, 0x020000 and 0x030000, then you need to convert them to numbers first using hex.
my @formatted_nums = (
'0x000000',
'0x010000',
'0x020000',
'0x030000',
);
$formatted_nums[1] = sprintf("0x%05X\n", hex($formatted_nums[1]) + 1
+);
print("$formatted_nums[1]\n");
