See if you are comfortable with this:
On Presentation B, instead of adding a button which when clicked, hyperlink
to the custom show, remove the button.
Now, add a rectangle that covers the entire slide.
Double click on the rectangle, set fill color to 99%. Line color to no line.
Click Ok.
Right click on the invisible autoshape, select Action Settings.
Select Mouse Over tab, set it Hyperlink to the custom show.
To make the mouse over works,
Click Add Effect > Entrance > Appear.
Set the Start from "On Click" to "After Previous".
Double click on the added effect.
Select Timing tab, set delay to 0.1 seconds.
Click Ok.
Save the presentation.
So here's how it works: From presentation A, you click on the link to
presentation B's Slide X. The invisible autoshape on slide x will appear and
link you automatically to the custom show.
--
Shawn Toh (tohlz)
Microsoft MVP PowerPoint
Site Updated: Sept 05, 2007
(Amazing PowerPoint animations, artworks, games here)
http://pptheaven.mvps.org
PowerPoint Heaven - The Power to Animate