actually there are other program things you can . . .there is an RSS feed thing you can use and recieve updates and such so yea you should be able to but I believe it works with some other install of something.
So if you can find a plugin for the player you want to use to control then there shoudn't be a problem or if there is a command line type command you can send you can use the !excute command
if you never noticed on Drake's maid if you click on her tie she changes to a different hairstyle and such.
So you just set hte first initial image then set the 2nd image but put it as hidden and in the case of the maid the code is
LeftMouseDownAction=!execute [!RainmeterToggleMeter Chara1] [!RainmeterToggleMeter Chara2]
So I threw this after my base image
So if I click towards the top of my hard drive info my c-drive folder opens up. Set path to a program exe and it'll open the program. I'm not sure if commands like .exe -window sorta commands work but if your program can use that you can always make shortcuts that do it or batch files. *scratches head* I guess I'll have to contiune to read more on it. It's pretty interesting
though I got ahold of a vector based 2d animation program so I"m not sure where my time is going >_<
O the quote plugin sounds interesting
Shows random image from your My Pictures folder as 200x200 thumbnail.
PathName=%HOMEDRIVE%%HOMEPATH%\My Documents\My Pictures\
I wonder if you can set a refresh on that so that after a certain amount of time it'll automatically choose a different image so you can have your different versions of a character load up
After another close read . . .what you're looking for is Windows Messages. But you need the codes and parameters to send to it so in the case of winamp you have to read the sdk to get that info