"Pod kiponom" song translation please

Our choir is about to perform a series of Eastern songs, among which the Croatian "Pod kopinom".

I'd rather know what I sing
Any help welcome,

Thanks in advance

LYRICS:
Pod kopinom pod zelenom tam je nje mu spavati, tam je nje mu spavati obe cal mi svilenc robec, ne rad bi mi davati, ne rad bi mi davati

Pod Kopinom

Pod kopinom pod zelenom

Tam je nje mu spavati,
Tam je nje mu spavati,
Obe cal mi
1. svilen robec, / 2. zlaten prsten / 3. zute cizme

(Oj) ne rad bi mi davati,
(Oj) ne rad bimi davati.
Ako njegva stara mati
Nece mi ga davati,
Nece mi ga davati

Well, first - I don't know what is kopin

Under...

Under ... under the green

That's where he should sleep (I think lol)
That's where he should sleep
He promised me
1. silk handkerchief, / 2. gold ring / 3. yellow boots

(Oj) he doesn't wanna give it to me,
(Oj) he doesn't wanna give it to me,
If his old mother,
wont give him to me,
wont give him to me


And, again, I am so not sure about any of this but I tried...

Thanks a lot. It does help. Hope we'll sing it more or less meaningfully

JF