Update "buildin" excel in a powerpoint with macro

Hello
I got a huge problem that I hope you people can help me solve. I am
trying to create a powerpoint with my mac (version 2004 of ppt) and I
got some excel charts that generates random numbers and calculates
abit in my powerpoint and when watching the powerpoint I want the
watcher to have the ability to "refresh" the excel charts to get new
random numbers but I have no idea how to do this. I thougt about doing
a macro but I lack the skills to create it so I wonder if somone could
help me with this.

/ Tithen_@gmail.com