On-The-Fly HTML/File/Page generator Script using 6 digit number

I am looking for a set of website scripts (PhP) that will accept a 6 digit number input from a visitor and then it send the user to that webpage /file if it exists (searches first). If it does not, it generates a temporary webpage using the number given (output only but looks like it snapped right to the webpage anyway (as if it already existed). The page generated uses a text-template provided as ([login to view URL]) to build the file and name the file using the 6 digit number. Again, the script(s) will create webpage files (.html) from [login to view URL] through [login to view URL] using a preset layout ([login to view URL])--as called upon by a website visitor. That file will be temporary (really non-existing, just an output on the screen). No actual file needs to be created, just the output that looks like the file was created. In other words, I will have a few webpages already built, for example: 390029.html. The program/script will "check" the file to see whether I have already created [login to view URL], and if so the program will not create a duplicate, but will create all the other files based on the remaining number sets (unused numbers) as an output file pretending to be the 6 digit file called. The idea is that by entering a 6 digit number into a box on my website, visitors can then be transported to that page. I have a special form to enter the numbers via buttons, so some modification my be necessary. Let me know if you have special experience with this type of work?