web form and .php script

i'm looking for someone to create an .html form that i can place on myWebsite. the data from that form will go into a .php script that must do the following: 1. take a user-provided url and access the url's webpage. 2. search the source code of that webpage for a piece of data (a string) 3. take that data, insert a different string in front of it, creating a new url 4. present that new url underneath the form on myWebpage so users can click on it it's really a simple script, i can go through the process by hand without issue, and can explain it in depth and provide websites that perform the same process to help clarify (via PMB).