Please see Hubal and Allah the Moon God?, Islam's God, and A Peek Behind The Crescent Moon Of Islam. It it true that the Hebrew El and the Arabic al are cognate, and both mean god; what follows identifies which "god" is being referred to. The "Al-lah" of the Koran is not the El Shaddai of the Bible.
Muslims are pretty clear that they worship the one true God of the Bible (they share the OT with Christians and Jews and are well aware of who Abraham's God was/is) and not the moon. Too bad you're confused.