Not silly at all. That's a pretty common question. The easiest and most direct way to convert such a model over to SimBiology is to convert each differential equation to a rate rule. You can find an example of that here.
It's more work, but another option is to reconstruct the network of reaction from the differential equations. That's what I prefer to do, sicne it allows me to build a graphical diagram of the reaction network. It can often be less error prone, since SimBiology does more of the bookkeeping for me. We've considered adding a feature to automatically convert rate rules into equivalent reactions, but that hasn't been implemented yet. But this is a good point of imformation as we prioritize what to work on next.
-Arthur
