how to ext script with bbwin ?

I don't usually do windows. 
I have installed bbwin from here http://jmac-software.blogspot.com/2012/03/xymon-windows-client-set-up-guide.html

I found below post via google ... but there is still large gaps in my understanding. 
 What format do you write a report in the bbwin tmp directory? Can I specify a column name ?


Hi Ryan,

I didn't understand why you use bbwincmd. You could use the externals
 agent to run your program every 5 minutes and your agent would just has
 to write a report in the bbwin tmp directory. Then, BBWin would take care to read the file and send the status to the hobbit server.

That would be much easier for you.

Don't you think ?

Etienne.


Can somebody give me more info or point me to any docs online? 
Thanks

Bakkies