// ok, we have a proper list now
// we could use assign and then eval "b<-data.frame(b)", but for now let's build it by hand:
String rn[] = {"1", "2", "3"};
long xp7 = re.rniPutStringArray(rn);
re.rniSetAttr(xp5, "row.names", xp7);
long xp6 = re.rniPutString("data.frame");
re.rniSetAttr(xp5, "class", xp6);
// assign the whole thing to the "b" variable