derivative rule syntax

Hello, 
Im tryin to derive few rows like this:
E#[*]=HQ_MANTUGR:A#[R69204ALLOC]=R79204ALLOC:U7#[MREA01]=AREA01:U8#[EUR]=None
is there any otpion i can use to tell the system to replace only the "6" in the account name R69204ALLOC by 7 to get R79204ALLOC and the "M" in the UD7 Name by A to get AREA01 ? 

if this requires a business rule and you have one exemple please share it with me 🙂

thanks for you help