EU Law: extra sentence on invoice

[deech123]

I’m working for a month now with my prestashop.
and something I’m looking for is this.

If I sell products to an other firm that is not located in my country, then I must provide prices without TVA.
that’s okey, I managed that.

But my accountant told me I have to add a specific sentence on the invoice.
The law tells us we have to add an article numbre and sentence from the lawbook
like §bis9...the goods are free from tax described ...blablabla

Is there a module or a way where I can say :
if the TVA = 0% then
add this extra comment to the invoice?

or better, that you can even check a clients name as :
client without tva
invoice with extra comment.

and this really on client niveau.
why? :
If I ship to an EU country I must added a text like §bis9 blablablabla
but if I ship to a non-EU with valid TVA number, I must add some extra text beside §bis9...

the best way would be to create standard messages (you can make as many you want)
and then on client niveau you can click if client is TAX free or not, and the messages what must be enabled on his invoice.

this would be the correct thing to do.
Now I'm working with the zones to show/ask TVA but think we can finetune this in this way.
A lot of our users would appreciate this I think.