EC Acquisitions/Reverse Charge

Hello everyone. I have a real mental block where EC purchases are concerned.

Am I right with the following:-
If I have a purchase invoice for say £100 (equivalent) from an EC supplier, where the VAT is 0% and the invoice is for goods - I would fill in the following boxes on the VAT return
Box 2. 20.00
Box 4. 20.00
Box 7. 100.00
Box 9. 100.00
Am I right in thinking that any invoice from an EC supplier, you would work out what the VAT would be if buying in the UK and put this figure in Boxes 2 and 4.

If I have an invoice for the same amount where the reverse charge mechanism applies. I would fill in the following boxes:-
Box 1. 20.00
Box 4 20.00
Box 7. 100.00
Box 9 100.00

I hope I am making sense!

Nicky