How to derive next character sequence

[Sudhakar_Pochiraju]

Hi,

I am looking for a help, I have a value in the system to read then derive the next in sequence to update the value.

For example, let’s say current value of a field is “BJ”, read the value then it needs to be updated as “BK”. Likewise if current value is “AI” then it’s needs updated as “AJ”.

Any idea, how to do it ?

Thanks,
Sudhakar