Something I've always wanted but haven't got round to creating is a command that would convert from camel case to pascal case to uppercase with underscores. It

Something I've always wanted but haven't got round to creating is a command that would convert from camel case to pascal case to uppercase with underscores. It would be awesome if you were able to yank text in one case and it would paste in a different case if it was being pasted on top of exiting text. for example if you had the code: #define USER_NAME_LEN const int userNameId; class UserName { }; if you did a search and replace for userName to replace with clientName it would update all cases correctly.