Reports in different language

[Nestor Stura]

Hi all,
I have a new customer in Holland and I need to invoice in English while my
system and legacy language is Spanish.

I know and have done customised reports but I do not know how to change
report's texts like "Factura" = Invoice or "Condiciones" = Payment terms,
that are built in the report.

Is there any easy way around? Or how can I change the invoice report
without losing my Spanish version.

Thanks a lot.
Néstor