How to find and replace regular expressions in Notepad++?

Question

Regular Expressions

Yes:
Source string -
abcd_12345 : abc take what is after "_" and substitute before " abc " I understand that in the same notepad++ I need to Find: ^[A-z0-9]*[_][A-z0-9].*$ Replace: with what? The text before and after "_" will be different, just like after ":". But the point remains to take the value after the "_" and substitute it after the ":".

Answer 1

^([A-z0-9]*)_([A-z0-9]*)(@.*)?:(.*)$replaced by\1_\2\3:\2\4