Customize/Adapt Joomshopping-Joomla

We are a professional photo lab. We have a website where we receive 90% of the orders. Our website are a Joomla template, with a online shop (Joomshopping). The online shop is only available after registration. Some details of the registration are important to define if the client will see the prices of the shop with tax or without taxes. It will depend of the country, as you can see at [login to view URL] (attached to this Project) , in some countries we will need to always charge VAT/Tax, but there are exceptions. The main problem is if a client is from EU (at [login to view URL] you can see it at the second line, it's marked with a red line) It will depend if that client have a valid VAT or not. And here is where the problem begin. We need this verification to be automatic. But what happens now is that if the client are from EU and fill with characters the field named "TAX ID/VAT No. *" the system do not verify if is a valid VAT or not. ([login to view URL]) What we need is: - When a client introduce his vat number the system automatically know if it is a valid or not valid VAT number. This way the system will know if he needs to charge VAT or not to the specific client. If client are from EU and have a valid VAT number, the system should not charge the tax. If client are from EU and do not have a valid VAT number, the system should charge him with 23% This is important to be all automatically. [What we are doing at this time, is to verify all the VAT numbers of the clients in this website: [login to view URL] we can introduce manually the VAT numbers and know if is valid or not] --------------------------------------------------------------------------- In the same software - Joomshopping - we have the need to change something in the orders. In [login to view URL] we can see the backoffice of the orders, there we have the information of the client that makes the order. Joomshopping allow the joomla administrators to edit the order as you can see in [login to view URL], when we do this changes it will accept me to change the name, address, etc. But it will always be related to the account that first make the order. And this is not what we need. We want to edit the order and change it all to another register client details, that already exist in the shop. -------------------------------------------------------------------------- So these are two different things to be done, if there is something that is not clear, any question please, do not hesite and PM.