The normal rule for the export of goods within the EU is that the goods will be zero-rated if selling to another EU VAT registered business. You need to quote their VAT number on the invoice and other export documents and you will need to complete an Intrastat form along with your VAT return.
From what you've said, I cannot see why your transaction would not fall under these rules but I would check with the HMRC helpline (no need to incur accountant's fees); they are normally very helpful.
Cheers
Whirls