CurrentShowPosition Property
Returns the position of the current slide within the slide show that is showing in the specified view. Read-only Long.
Remarks
If the specified view contains a custom show, the CurrentShowPosition property returns the position of the current slide within the custom show, not the position of the current slide within the entire presentation.
Example
This example sets a variable to the position of the current slide in the slide show running in slide show window one.
lastSlideSeen = SlideShowWindows(1).View.CurrentShowPosition