Pinyinated 'm' with four tone marks?
Tones are only applied to wovels. There are no tones associated with consonant "m", so you have to assume a prefix wovel like "e" before the "m". Unicode-wise, you can get an accented ḿ but no other variants.

Yes, you see accented "m" in dictionaries, but they are outside pinyin, and also outside unicode.