Inserting math subset and superset symbols into office word

Question

I want to insert this equation into the MS Word using Equation Editor:

I have tried:

(a+b)^n=n_(C_n ) a^n

which results:

Is this the best it can do?

Solution 1

I use superscript with space in the fist position and the k value in the superscript position, followed by a subscript with a "C" in the first position and the n value in the subscript.

Solution 2

The best I can do right now is the counter-intuitive

(a+b)^n=\zwsp ^n C_0 a^n 

because everything else either puts a space between the superscript n and the following C, or requires (_^n) before the C, which results in poor layout.

Comments

[Jukka K. Korpela]

Do you really need to use nonstandard notation for binomial coefficients? There are two standar notations, n over k in parentheses and a C with k as superscript and n as subscript, both on right.

[cpx]

I'd like to use both the standard notations.