Required payment information based on address field

I'm searching for at way to force the customer to enter specific required information, based on selected payment method.
For public institution, it's required that the invoice is shiped through a digital portal, and for that reason, I need the ID (named EAN) from the public customer.

Case: I've created a payment method, type 'HikaShop collect on delivery payment plugin' and named it 'EAN'. The customer select EAN as payment method and before submitting the order, I want the system to force the customer to enter the EAN number. Either in a specific form field, or make an address field required, if customer select 'EAN'.

Is there a way?

Thanks Nicolas - that did the trick!

Hi again,
New challenge - this time shipping method.

I'm looking for a way to make a required field available, if customer choose a specific shipping method. In case of B2B shopping, our shipping provider demands a VAT registration number to proove they are a valid company. All I want is to force the customer to type in their VAT number, if they choose a B2B shipping method - no other validation on the field than *required?

It it possible?