|Even if you don't have a static IP account from your provider, it's possible your IP will stay the same all the time.|
For example, my provider for my home internet gives me my TCP/IP settings via DHCP. As long as the MAC address of the piece of equipment their service plugs into doesn't change, my IP doesn't change....even though it's DHCP.
This may be the case for your service and if it is, then you can easily connect remotely.....I know I do it all the time (connect from work to home in my case)
It's easy enough to check, just connect to the "What's my IP" website at work a couple times a day over the span of a few days. If it never changes, it's static enough for your purposes. Also, you could call your provider and ask them outright about the lease time on your IP and how often they change, if they do.