Controlling in Excise

Dear All,

We would like to have Lock in system so that if excise credit is taken in RG23 Part 2 then no reversal of original GRN is allowed. I had a look in messages for 8I & 4 H in Se91 but i could not able to find out correct message number.

Can any one tell me the exact message no. for above control?

Thanks in advance.