how to add a scriptbased custom product to virtuemart

[Eckelstone]

Okay first things first : this project and the community behind it is awesome 

Now straight to the point : I have a php script to calculate and create a custom product with Attributes like height width materials used and so on ... prices are also calculated and everything ist fine ...but how do i connect to vm? do i have to add a new  product in the database add the price and just "link" to this new created product or is there another way to get the newly created product into vm?

help is very much appreciated even hints just something to start looking at for me .

thank you very much

yours
stone