Try it with the extra space removed:

\[\[(*)\]\](*)^13

I have realized that this probably isn't what you want... you want it to NOT see multiple square brackets as being nested... but it does. The selection starts with the first open square bracket, and ends with close square bracket followed by a space then maybe characters then end paragraph. I doubt you can overcome that it thinks everything between the first square bracket and the end square bracket is nested, but ... not positive.