Conditional Value List defined by a Portal Field

I am developing a database designed to contain examination questions. A growing issue is the need to accommodate several tiers of questions, 3 tiers, along with related answers/scoring keys. The organisation requires that all are visible on the one page (otherwise I would make another layout linking back to this using scripts), the 'Question Bank' encompases the group of records, however the 'Question' is the core table for this layout.

1. Question Bank (2)

2. Questions (2.1...)

Question Answers

Marks

3. Subquestions (2.1.1....)

Subquestion Answers

Marks

As such I was hoping to use a portal within a portal to relate subanswers to subquestions only to find that you CANNOT successfully place a portal in a portal (or so I've found and read) . The solution seems to be a Cond. Value List. BUT I need to create a relationship between the subanswers and their subquestion so that only the answers for that particular question are listed. I have the value list but the condition isn't activating and I am getting a list of all the subanswers in the subanswer field, not just those for that question. The field I have related, 'subquestion number', is within a portal on that particular layout which seems to be preventing the value list from identifying the value it needs to relate to.

How do I get this to work? What am I missing? If I have to build a loop script instead I will be lost

Thanks

Nattani

PS: I have attached a screendump in word to help. I cannot attach the DB itself due to confidentiality issues.