I propose an application called by the button that stores and selects your random URL from a flat text file. If necessary, the text file can be encrypted so that only the application can read it. Editing can be accomplished with NotePad or other text editor run as a child process from within the application. I can produce a high degree of randomness exceeding most common random number generators. I can incorporate encryption for your text file, also my own algorithm.
JavaScript or PHP can be used to invoke the application.
Once selected the random URL can be passed directly to the client browser dynamically without revealing itself through "view source" options. HTML parsers will reveal only the call to the application and one or two variable names, not any URLs in the text file.
I have developed a random number generator that conforms to the standard poisson distribution at a 98% confidence level. I have also developed an encryption algorithm that uses a rotating 128+ bit key size generated within the algorithm.
Upon completion, I will provide you with the source code (except the random number generator and encryption algorithm which will be provided in binary format only) and a functioning executable. I will also provide any necessary JavaScript or PHP code used to call the application.
Thank you for your consideration,
Stan Helton