Carrier module using external web service with dinamics return

[deustotech]

Good Morning,

I would like to create a module that añadiese different shipping methods to process purchase prestashop, depending on a number of features. For information about each shipping method you need to connect to a web service itself that should receive the following parameters:

Source address - destination address - weight - High -wide - long

The last four parameters belong to the package features. The first problem I find is that I do not know how to get these parameters from data prestashop, then I would not know how to add these methods to the shipping methods that appear by default, since the own methods are not static, but change depending on the parameters received. And therefore it could not be added to the database of carriers of prestashop.
Po Finally, if you can help me once corrected both problems to update the shipping cart and properly take a proprietary method if the user selects it.

Thank you so much for everything,
Greetings.