upgrade to not latest version

Hello How can I update PVE only to version 4.2-17 from 4.1.1? I can't upgrade to 4.3, because I have software they not working on 4.3 and must wait after will be added update. Have on sources.list pve-no-subscription, and when I dis-upgrade then proxmox will upgrade to 4.3. Is there a way...