Just edit the save, since you mentioned an R4 in your post, and it sounds like you have one, you can save lots of trouble by loading the save and editing the necesary parts and then just hitting "Save".
Click on "Save Box" on the pearl save, and then save them to a new folder then press "Load Box" on the platinum save.
Rinse and repeat until all of the pokemon are copied to the platinum save.
If you make the button put this code on it:
on (press) {
gotoAndStop(FRAME GOES HERE);
}
I've actually made a version that is a lot harder to make. It loads the images dynamically (meaning when you need them, not when you load the one file)
As for making it look the same in a browser, just load up dreamweaver and insert the swf into a html file.