How to change product's price manually?

[OriyanJ]

I've inserted a plug-in custom field that I want to be able to affect the product's price. Either by clicking or choosing a value from a drop-down.
As for a simple example -



Seems pretty easy. I was hoping anyone would be able to direct me somewhere, then I'll manage on my own.

[GJC Web Design]

std custom field select with a value...

[OriyanJ]

What I mean is, I want to know how to do that without setting a price value in VirtueMart's back-office. I'd like to call the proper function that adds a price value. I know that for what I describe, a simple custom field would work, but I'm looking for more complex abilities.