Thank you all for the input, it's much appreciated.
Obviously, I'm only doing this project in my spare time, as a learning exercise (an exercise made more interesting/fun because I like text-adventures). I have no aspirations to one-up mature authoring tools like Inform 7 or TADS 3. However, I am going to incorporate such elements in my game language that -- to me -- are easier to use.
HollowLife, thank you for your offer. It's much appreciated. If I understand you correctly, you're staying that if I can come up with a working interpreter EXE, I can supply that, plus a binary game file produced by my game compiler, and you can give me source code that would incorporate those two files into an EXE. What language would you supply this in? I am only familiar with C# and (to a lesser extent) Visual Basic. However, I do have a couple of different C/C++ compilers.
Eoin, thank you for the link, and the advice.
You'll need your interpreter to not be fussy about where it gets the binary source data from. So it should be able to read it from a file, and also quite happily accept being given a raw pointer to the data already in memory.
I was planning on using .NET's object serialization capabilities, so that my compiler would read in the source file, syntax check it, and if it doesn't fail any syntax checks it would incorporate the data read in from file into game objects (rooms, items, actors, etc.). The resultant compiled game file would be a master game object (containing all other objects), serialized to disk.
Then, the interpreter would deserialize the file and cast it to the master game object, then proceed to use that master game object's properties and methods to produce the interactive game that the end-user experiences.