Injecting application into existing document?

Is there any way I can inject applications created with TMS Web Core into and existing document?

If I set a Form's FormContainer, I can control where it shows up inside the form's html document, however I would prefer to be able to control where is appears in another document such as the project.html document.

If I have to mix technologies where one technology is producing an html document, and I want it to inject my application (created with TMS Web Core) into that document to appear as part of that document, I currently don't see a way of doing that. (other then an iframe, which introduces several other issues when displaying additional forms from within the application).

The first obvious thought was via IFRAME indeed. 

Not sure if there is an obvious other way, this would require deeper investigation/research.