I've got my nameservers pointed to 1st IP adress. Is there any way I can point subdomain to a 2nd shared IP adress (hosting)? It's not that simple to just point subdomain to 2nd IP because the hosting uses multiple virtual apache hostings.
you just need to edit your DNS table in your dns provider panel (if they give you the way to have subdomains).
You just need to ad a new A record like:
18.104.22.168 A subdomain.yourdomain.com.
Every dns provider have a specific panel, just looks at other records to do the new one.
If you need a DYNAMIC subdomain redirect, I suggest you to use dyndns.org