If you mean an expression (and even worse in a single step) then I'm 99% sure it is impossible.
Expressions help to work in the TestStand ecosystem, so an engine, seqedit, or manager controls. I think the cursor is outside of this ecosystem. What is more, expressions are pretty limited. However, there are methods like Engine.GetInternalOption one can use to return, for example, an ApplicationManager. But as you may see it returns it as a variant, so you need another step (ActiveX) to type cast.
Try to use Windows API and .NET or C/C++ DLL adapter instead.