Concatenate mp3-Files on Macintosh

[R. Hillen]

Hello list,

I want to write a tool for Mac OS X, which asks for a folder with  
some mp3-Files within and after that concatenates them into one file.

By googling I found this tip:

1. Place mp3s on Desktop
2. Open terminal and type cd Desktop
3. Type cat *.mp3 > giveitaname.mp3

I tried and it worked.

Now I want to script it in Revolution; as I don´t know anything about  
unix and shell and so on, may anyone helpfully tell me, how to script  
it:

-----
answer folder "Where are the mp3-files to Concatenate?"
put it into sourcefolder
ask file "What is the path to the resulting file?"
put it into targetpath

--and here should follow something like:
--do shell "cd sourcefolder"
--do shell "cat *.mp3 > targetpath"
------

Thank you for your help.
Richard.