PPT07 - Call Macro from action button and pass a variable

[got2surf2]

I have an Excel VBA routine that generates a Powerpoint slide. On the slide is a depiction of a time line with block arrows points to specific points in the timeline. The number of block arrows is variable. I want a standard macro to be executed when i click on any one of the arrows and the macro needs to start playing a media file at a porticular point in time. I can't seem to figure out how to pass the starting point to the macro - the Action setting only allows me to specify a macro by name with no values being pssed. My VBA code specifically assigns the macro to the block arrow on a MouseClick - that works when the underlying macro does not take any parameters. When I have a macro with parameters the MouseClik call does not do anything.

Thanks!!