You can always use $name for any operations with global name, either simple as ^G or with subscripts as "^G(1,"something").
It is intended for this.
In your case it would look like:
or you can set global name with subscript, e.g.:
It's very convenient to use indirection operator @ in this case to deal with variable with global name inside.
E.g. you can refer to any subscript with global inside x, like this:
which would be equal to:
And with your $Order example you can have:
USER> set x=$Na(^G(1,"second"))
USER> set @x@(1)=2
USER> set y=$O(@x@(""))
USER> write y