Q&A Plugin

Hi,

Sorry to ask something like this but have not found anything about it and I have spent many hours on google.

I need a Plugin Q & A with multisite support. What I need is:

1 .- Any person can ask a question from a form in a page.
2 .- The question remains pending until approved and answered by an admin.
3 .- The question is published in a list of Q & A.

I know it's a very specific requirement but want to know if you know any plugin with these features

I tried dozens of plugins but none is what I need, may i have to develop from scratch, but before to do it, i ask =)

Thanks in advance