Need more specific string comparison warnings

I want resharper to suggest a standard string comparison in my c# code. Currently, if I turn on the string comparison option, I can get a suggestion when I do something like this:

a.ToUpper() == b.ToUpper()

but not when I just do this:
a == b

Is there a way to get it to work without the ToUpper()? Also, I want it to tell me when I do not put the StringComparison operator there. Our standard is OrdinalIgnoreCase. let me know. Thanks!