This was the suggestion I received. I do not know if it would cause a conflict with the music code.
I would not use the circumflex modifier over a number. I do believe it is intended only for letters. What you can use is the "hat over previous item" (dots 5, 156). This is discussed in the Guidelines for Technical Material, section 12. It is used with numbers and even with letters in a technical context. Unlike the accent/modifier signs, it is placed after the digit or letter.
Hope this helps!