If I have a page open with URL "http://blahblahblah/blahblah/getting+started.html", the script I need should open a new tab with the URL
http://(server_name)/getting_started_txt_(random_alphanumeric_code_here).html
Note that there is only one file on the (server_name) server which matches that getting_started_txt part and the rest of the file name can be anything.
Also note that the source URL has + between words and not spaces, underscore.
But the new URL must have
1. + replaced with undercore
2. _txt_ suffixed afterwards
3. ability to pick the first html file that matches getting_started_txt_<random_alphanumeric_code_here>.