C# Equivalent for C++ Macros and using Auto<> Properties

I have some auto-instantiation code which I would like to apply to about 15 properties in a fairly big class. The code is similar to the following but the type is different for each instance:

protected ComplexType _propertyName;
public ComplexType PropertyName
{
    get
    {
        if (_propertyName == null) {
            _propertyName = new ComplexType();
        }

        return _propertyName;
    }
}

To repeat this in C++ (as there are ~15 instances), I would have used a preprocessor macro but I notice C# doesn't support them.

I am wondering if anyone has a recommendation on how to do this cleanly in C#?