Yes, that should be possible.
I always connect trough my domainname coz I'm to lazy to set up 2 settings in putty

have you set up your static IP
I set up a static IP, the /etc/network/interfaces looks like this:
Make sure you use the right network, I use the 192.168.1 things.
auto lo
iface lo inet loopback
address 127.0.0.1
netmask 255.0.0.0
auto eth0
#iface eth0 inet dhcp <---- I commented this one
iface eth0 inet static
address 192.168.1.201
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
gateway 192.168.1.1
address = internal network address
the gateway = your router
I forward the needed router ports to 192.168.1.201
This is my list of ports (maybe useful):
FTP-Server TCP 21 192.168.1.201 21
HTTP-Server TCP 80 192.168.1.201 80
OpenVPN TCP 1194 192.168.1.201 1194
Webmin TCP 10000 192.168.1.201 10000
SABnzbd TCP 8080 192.168.1.201 8080
VPN TCP 1723 192.168.1.201 1723
SSH TCP 22 192.168.1.201 22
VPN GRE 192.168.1.201