Add additional information on sales invoice

Hi,

This question concerns AX 2009.

I am looking for a way to add a text on a sales invoice that is triggered by customer and/or customer group. So far, I have only found two ways to add a note to the invoice:

• Via AR > Setup > Forms > Form notes and choose Sales order invoice. Here I can setup a note based on customer language setting. However, I cannot do this setting based on anythin else than language setting.
• Via AR > Setup > Forms > Form setup and activate "Include documents of type" for "Note". Then I can add a note on the actual invoice via the document handling Icon (of the type "Note"). However, this requires me to create a new note for every sales invoice.

What I am looking for is how to automatically add a predefined note based on the customer or customer group when generating a sales invoice. Is this possible?

Thanks,

Rebecca