Hi,
A lot of the information you need is in Adobe's scripting guide http://www.adobe.com/go/learn_lc_scriptingReference Also there is a very useful Adobe guide to Calculations and Scripts (and while it is for version 6 it is still very good because of the way it is laid out) http://partners.adobe.com/public/developer/en/tips/CalcScripts.pdf
The Javascript could be used in the Layout: Ready event.
For italic font:
if (...some test...)
{
this.font.posture = "italic";
}
else
{
this.font.posture = "normal";
}
For bold font:
if (...some test...)
{
this.font.weight = "bold";
}
else
{
this.font.weight = "normal";
}
The script will change the font for the complete field. I don't think you can change parts of a field.You can also change font colour and font type (the guides above will help).
Good luck,
Niall