Tunneling Question..Help!

[owner-ssh]

I'm using ssh2 on a SunOS 5.7 machine. I would like to be able to ssh into my 
DMZ machine inside of my firewall but I'm not sure how. My DMZ machine is not 
Internet routable.  I think it would usually be just launching ssh on the 
firewall to a port that passes through the firewall (SSL). Will this method 
still work? Will sftp work in the same fashion? Is there a better way for a 
machine outside of a firewall to tunnel into machine through a firewall??

Thanks to all responses...
-Chuck