If you just said "Boruch Atta Hashem Elokei-" you can finish it with the end of the passuk (and you can say "baruch shem..." after that):
ברוך אתה ה' אלוהי ישראל אבינו, מעולם, ועד-עולם
If you already said Elokeinu, you may be stuck, since there's no passuk that has all those words together. I'm not sure if DoubleAA's suggestion would work since you used "ברוך אתה" as part of the phrase, so I think at that point you should just say "Boruch Shaim"Shem".
Source Update: Kitzur Shulchan Aruch 6:4.