You can edit a PDF form with the appropriate software like Adobe Acrobat. I actually that software and I can edit the form elements.
Here's the "formula" behind the DP calculation:
var a = this.getField("stat.ag.temp");
var b = this.getField("stat.co.temp");
var c = this.getField("stat.me.temp");
var d = this.getField("stat.re.temp");
var e = this.getField("stat.sd.temp");
var f = a.value + b.value + c.value + c.value + c.value + d.value + d.value + d.value + e.value + e.value;
event.value = (Math.round(f/10));