It was part of a "birthday basket" that was given to me (along with the Beersmith), so I figured I would use it. I was thinking I would steep some caramel flavored grains in it, add a light DME, and maybe additional hops?
A hopped extract is made by the maltster and is a boiled wort with bittering hops added and perhaps some flavor and aroma hops. That wort is then condensed into a thick syrup, giving you your hopped LME.
The instructions may say
not to boil the hopped extract, but just add it to your boiling or hot water. That is, so you don't change the flavor and bittering profile. After chilling that should give you a pitchable ready wort, quickly and easily, providing bittering, flavor, and some aroma from the hops. You reconstituted what the maltster condensed, similar to a can of soup.
Since we don't know what specialty malts and hops were used you can do some research on the net or try an educated guess.
Now this canned extract can be used as a base to expand on, like you said, by adding more hops and some steeped crystal malt.
You could try to dissolve a little bit of the syrup to a gravity of 1.030-1.040 and taste it, and see where it stands. It will be sweet, but give you some idea of what it contains. An opened can should be re-sealed as tight as possible and stored in the fridge, but not for too long. It will become stale or spoil.
Will be an interesting adventure. Keep us posted which way you're taking it.