MS-Word equation editor: How do I add an exponent to the left of its base
Workaround found here: https://superuser.com/questions/1230648/how-to-write-superscripts-before-symbols-in-equation-mode-in-ms-word/1230654
Type "^2 P " (with a space between 2 and P), which will put the 2 in superscript in front of the P, but will also add a dashed box for a subscript.
Then comes the workaround: type a space in the square! It'll disappear.