Use Notepad++ to Capitalize Letters in Snake Case

I’m using Notepad++ to find/replace and can’t quite get what I need.

How do I replace lines containing “+ 6 random digits” beginning of line > replace to “PC+numbers” ex: “123456, to PC123456, [closed]

Closed 1 min ago.

Notepad++ replace lines containing “+ 6 random digits” begining of line > replace to “PC+numbers” ex: “123456” to “PC123456”

As mention, I will need your kindly help in order to replace on each line of the notepad++ file that starts like “123456” to “PC123456” . thx in advance