The FAA regulations do not permit the issuance of any more than a Private Pilot certificate based solely on a foreign pilot certificate (see 14 CFR 61.75). For issuance of a full FAA Commercial Pilot certificate with Instrument and both Single and Multiengine ratings, you will have to present a logbook documenting sufficient experience to meet the requirements for a Commercial Pilot certificate with those ratings, take the Commercial Pilot Airplane written test, obtain an instructor endorsement recommending you for the practical tests (that requires at least three hours of flight training from an FAA-licensed flight instructor for each practical test), and take practical tests in both single and multiengine airplanes. Contact the Flight Standards District Office where you live (and the FAA does have FSDO's in Europe) for details.