The XML is no problem at all now. I've figured this part out on installing Agyria Player onto my own site. The problem I have is fully understanding what is required of the script.

1 of 2 options:

1. A preroll advert runs - then main video - then preroll

or

2. An advert runs once and then the main video.

I dare say that if giving the time to study everything I will be able to come up with an add-on which would allow this to work.