VirtualBox - How to forward connections to guest SSH server!!

To set the rule:
VBoxManage modifyvm "VM name" --natpf1 "guestssh,tcp,,2222,,22

ps. TCP is replcable by UDP

To remove the rule:
VBoxManage modifyvm "VM name" --natpf1 delete "guestssh"

ps. VM must be shutdown while setting.