What is the proper way to access a variable contained within a namespace from ARM assembly

Normally, I can access a c variable form a S file with the following (shortened for brevity):

// file.c
  int _tester;

// file.S
.extern _tester;

ldr r0, = _tester    // load c variable _tester in to register0

However, I am unable to access this variable the same way:

// file.cpp
namespace earth
{
  int _tester;
}

I realize the name is getting mangled. The question is, can I access that variable without looking up and hardcoding the mangled name in the assembly file?