I think you meant:
Here's a head start this will allow you to type /mp3p in a channel and it will prompt you to go find your MP3 then it will play it through your speakers and will relay a "spam" msg to the $active channel.
As the alias is mp3p. Anyways you should probably turn $sfile into $$sfile you probably know the reason behind this. Also, the parameters aren't quite correct but it's no biggy.
$$sfile(C:\,*.mp3,Select Mp3 File) - The title would be *.mp3 and your OK text would be Select Mp3 File.
Use $$sfile(C:\*.mp3,Select Mp3 File,OK)
To the OP: The double $$ means that this command will only be executed if a parameter is specified. So if you click cancel without selecting a song you're going to get an error.
alias mp3p {
var %mp3.m
splay -p %mp3.m
msg $active I am current playing $&
$+([,$sound(%mp3.m).artist,]) -/- $&
$+([,$sound(%mp3.m).title,])
}
I added $& not necessary but makes it a little more clearer rather than just stuck on the same line.