As far as i can remember, there is no need for scripting to do this…
if this doesn’t help, we can continue the talk. 
EDIT:
It depends wether the VST “understands” PC-changes generally - if it doesn’t, it is not possible to do.
And it also is not recommended to use variations to switch between patches. Better use diffrent rackspaces for this, which will give you some benefits as (e.g) patch-persist.