How to suppress warning (converted from error) in IAR EWARM 5.4

I had a logging macro that takes a variable number of arguments. This macro will be processed by GCC in a non-integrated context and will expand to valid C code. Despite this, IAR EWARM gives the error "[Pe054]: too few arguments when calling a macro" wherever I call the macro (thousands of places)

EWARM provides diagnostic configuration for converting these errors into warnings (and, oddly enough, the code compiles when you do this (ie "error" is not a compilation error, the compiler is just dumb))

The problem is when I try to convert Pe054 to warning first, then try to suppress it, I cannot do the latter.