Yes, you can do this. Edit "OnPreviewRender"
dim preview as xpTextObject
dim dir, slide as xpSceneDirector
self.GetSceneDirectorByName("IN", dir)
self.GetSceneDirectorByName("IN-SLIDE", slide)
self.GetObjectByName("prev", preview)
if preview.text = "1" then
dir.position = 0
end if
if preview.text = "2" then
dir.position = 10
end if
if preview.text = "3" then
dir.position = 20
end if
if preview.text = "END" then
dir.position = 90
end if
So just set up radio buttons for your different preview points.
#XPression