Hi and welcome to the community!
Sorry you didn't get an answer yet, and in fact I probably cannot give you a satisfying one either.
AFAIK, the right mouse click behavior cannot be changed in Impress yet.
The support for wireless devices is not ideal so far, as shows this issue
about a similar problem.
So you could file a new issue
of type enhancement
, as it is certainly a good idea to allow to define the right mouse button function differently.
As a workaround, maybe the driver of your wireless device allows the assignment of a key to the right click. So you could define arrow left
or arrow up
to the right click in order to get the slide back function.