a url link using the data from ContactForm

In fact I would like to have users:
1) fill out the form I create online;
2) save their data to a db;
3) then immediately (for example, when they hit a Submit button) have the data populate the fields in an online pdf document so they can view it online; and then
4) enable the user to print the completed form;

Here is what i get :
https://trail2licques.free.fr/index.php/bulletin-dinscription/

It’s ok but how to get the data based on IP adress (Submitted From). So only the user get his own data ?