VPN problem connecting remotely

I too am a novice with this type of thing. We have Snapgear 300. It is
configured to access remotely. We have one copy of osftware with 4 concurrent
user licenses, that need to access main office where software is located.
Second office is fine accessing through network, but I need second location
to access the files to use the software. Snapgear said find out what port
software company is using, software company says it doesn't work that way. No
further instructions. Help?