set a default for override and manufactuere fields?

[Snostar]

In order for the "+" to show to add to cart on the front end of my site there needs to be at least a value of zero in my override field under product pricing.
My import program does not have this available field, Is ther a way to globally set the default to zero?

I would also like to set the manufacturer dfault to an emptty field is that possible? how?
Thanks!