automatic adding combinations

[overdoze]

Hello
I work with version 1.2.5 and versions of products I use.
I have over 680 products which I shall make three combinations for each, but you imagine the time it took to create it.So I think has a code (in php) to insert the variations for each product.I don't know how does the inclusion of combinations for a given product in the database so I need a helping hand to understand how this stain is the + or insertion feature combinations to use it in my code.
In which php file I can find the code for inserting the combinations.
Thx