Two suggestions for you:
One - No code
Insert an obect such as an auto shape or a square or a circle. Format it
the way you want it. Right click the object and select action settings. On
the Mouse Click tab select Hyperlink To then select Slide ... When the box
pops up, select the slide you want to to goto when you click the object.
When you are in presentation mode, this will take you to that slide.
Two - Some Code
Insert a command button on a slide. Go to the code behind the button and
enter the following:
activepresentation.Slides(1).Select
Where the number 1 represents the slide you want to activate. When this
code is run it will activate the slide specified.
Hope this helps.