You could also use Query (but I would most likely formula + update/join method):
Names Default To Here(1);
dt1 = New Table("Untitled",
Add Rows(4),
New Column("Col", Character, "Nominal", Set Values({"america", "america", "test", "test"})),
New Column("Val", Numeric, "Continuous", Format("Best", 12), Set Values([1, 2, 3, 4]))
);
dt2 = New Table("Untitled",
Add Rows(2),
New Column("Col", Character, "Nominal", Set Values({"ame", "rica"})),
New Column("Val", Numeric, "Continuous", Format("Best", 12), Set Values([11, 22]))
);
wait(1);
dt3 = Query(
Table(dt1, "t1"),
Table(dt2, "t2"),
"\[SELECT *
FROM t1
LEFT OUTER JOIN t2 ON t1.col like '%'||t2.col||'%'
]\"
);
-Jarmo