import com.eviware.soapui.impl.wsdl.support.http.HttpClientSupport
def myCookieStore = HttpClientSupport.getHttpClient().getCookieStore()

import org.apache.http.impl.cookie.BasicClientCookie
def myNewCookie = new BasicClientCookie("mycookiename", "mycookievalue")
myNewCookie.version = 1
myNewCookie.domain = "my domain as IP"
myCookieStore.addCookie(myNewCookie)