You can't copy the configuration as-is, but it can be imported after a few minor changes. The most important change will be that the interface names have changed. On a standard 5GT they will be named "trust" and "untrust". In a similar configured SSG they will be named ethernet0/0 and bgroup0.
Off the top of my head, you'll have to change the interface names in the following parts of the config:
- the interface definitions (set interface)
- the VPN definitions (set ike gateway)
- the routing table (set route)