Ok its not an ideal solution but it is something. You need to create a pointer that you can drag around. This is basically a shape. You dont want to try and drag a small shape around though because the remote display will not update until you let go of the mouse button after moving the shape so you want to be able to easily move it and such. Here is my suggestion.
Create a big rectangle. remove the outline and set the transparency to 99% dont do 100 or you wont be able to click on it without getting the border.
Put a mouse pointer icon on the top of it. You can use an Icon in Powerpoint (search pointer to find a black one) If you want it white change the color. put this pointer over the rectangle and group both together. Now when you move this big group around your audience sees the mouse pointer.
Since groups can be a little finicky with sub selections you may also consider converting this pointer to an image by copy > paste special > and png.

This "pointer" would need to be copy and pasted on each slide of you presentation.
Not the greatest solution but it is a work around.