Custom Browser Creator and Re-Brander Tool

I need a piece of software that can create a custom browser. I thne need a way to set the startpage and have a variable in the startpage, in case I want to include an affiliate link or userid. So a variable that can be set initially and then changed after the fact. Example I create a browser that points to my affiliate link for a product. The affiliate link can be set by me creating a variable. example: [login to view URL]<affID> I set the global variable in this case. I want to be able to distribute the application and then the variable changer needs to be a separate application that opens the Executable of the browser and then gives the user options to change the variables etc . This variable application needs to have a password option to protect peoples browsers from been changed. I would like a way for a user to logon, open the EXE of the browser and change the variable if they want. So in the example above they can then have their own affID inserted or they can change the entire URL if the variable allows for it.