We don't directly support external control other than generic remote controls via the Slide Show mode. We do, however, have some information in PDF form that may be useful if you are sufficiently knowledgeable in programming or interfacing PC applications together. It involves the use of an automation software package called Girder, and it can enable some pretty impressive capabilities if you dig into it and are creative. Please see the attached PDF file for more information.
Maybe at some point down the road we can implement more control capabilities into MediaShout, but for now this is about the only option we know of. As always, if this is something that you are really passionate about having us add in future versions of the software, please go to our Get Satisfaction forum and click on the Share an Idea link to let us know what you'd like to see in the future. We can't make any promises, but we will take the ideas submitted into consideration.