Editing RSG fixture file

[MJKEGGEN]

Please can someone advise how to control the overs attribute in these files. For example, some have overs="0" and others such as the national league fixtures have overs="2". Now that certainly doesn't mean 2 overs from what I can gather must be a code. If i wanted to change the fixtures to 20 or 30 overs can this be done and how?

Thanks for any help!
MK