N.Y. C.P.L.R. 303

§ 303. Designation of attorney as agent for service. The commencement\nof an action in the state by a person not subject to personal\njurisdiction is a designation by him of his attorney appearing in the\naction or of the clerk of the court if no attorney appears, as agent,\nduring the pendency of the action, for service of a summons pursuant to\nsection 308, in any separate action in which such a person is a\ndefendant and another party to the action is a plaintiff if such\nseparate action would have been permitted as a counterclaim had the\naction been brought in the supreme court.\n