Hosting of interactive content

Hi - I am new here so please forgive me if I have posted in the wrong section, or if this is a topic that has already seen a lot of discussion. 

Here's my question - 

I have an on-line e-portfolio system. We have developed the ability to deliver e-content to our usersfrom wiyhin the e-portfolio - so that's all good. 

However, I am struggling with interactive content. 

What I need to do is serve users an interactive workbook, which contains knowledge content, and also interactive tasks. The user needs to be able to edit that workbook, then when they save it their edited version needs to auto-saved back into their e-portfolio. Or perhaps the link from their e-portfolio to the workbook now needs to point exclusively to that user's edited version of the workbook, rather than the original virgin version.

So.. I am thinking that the e-portfolio simply needs a link to the externally hosted workbook which the user completes, and then they are returned to the e-portfolio. Within the e-portfolio, whenever they re-access the workbook (or whenever the learner's assessor accesses the workbook), they need to be taken directly to the edited version the learner saved. We have multiple learners, all of whom would need their own workbook. 

We are comfortable carrying out integration work if necessary.

I am perhaps not describing that very well - please ask for clarifications if that's the case!

The question is, therefore, is this possible and are there organisations that we could link to, that would provide this kind of capability?