I haven't tried the following code, but it's the only thing I can think of that would work in SqPlus. It may only work on tables or class instances, though:
SquirrelObject obj = SquirrelVM::GetRootTable(); //Substitute for your object here
BindVariable(obj, &myMember, _SC("myMember"));
Hate to toot my own horn here, but if that doesn't work out for you, you may want to take a peek at
sqrat. It provides mechanisms to do what you're looking for:
myClass.SetValue(_SC("myMember"), &myMember);
Good Luck!