There is a reason why people keep asking "How do you spell it?" when being told a name in English. The counterpart is, "How do you pronounce it?".
Even with "long a", I still can't tell how would you want to pronounce "Rach". I can come up with 4 different pronounciations right now: "Ra-ah-ch", "Ra-ah", "Ra-sh", "Ra-kh".