How do I create a COM server?

My company makes computer-readable meters and several years ago I used RealBasic to create a meter reading and billing program. I have now been asked to create either an ActiveX object or a dll that can be used by a third-party software vendor to retrieve meter readings. The LR has nothing relevant when I search for ActiveX and dll. Can I create either one of these types of objects? A COM server would be ideal. Where do I start?

Unfortunately, Xojo cannot create COM objects or DLLs. You’ll have to use another language.

I was afraid of that. I think I can accomplish the same goal with a service app that communicates through an http socket. It will be cross platform too.