Try the next adapted way. No need to function, if it does not return anything:
dim h as Object
set h = createObject("Excel.application.12")
h.visible = true
To use the alternate version, try createObject ("Excel.application.16"). If not, the default version is picked up automatically...
Since I have never needed two different versions, I am unable to test it. However, I used Corel versions, which operate in a similar manner. In the case of Corel, there are certain variations between the versions that affect how the same thing is done. I created some programs, and I had to update them all in the event that any changes were necessary.