Kevin, there's nothing Yiddish about Hevenu Shalom Aleichem – it's Hebrew, and Israeli. Although it appears that it actually traces back to a German cigarette advertisement where "Wir rauchen Salem Aleikum" ["We smoke (a brand of cigarette called) Salem Aleikum"] was sung to the tune now associated with Hevenu Shalom Aleichem. Type "Wir rauchen Salem Aleikum" into the internet (if you're interested) to trace this back.