MIR4 in change mode

The transaction MIR4 is for Display Invoice Document.

I have to tweak the functionality a bit and directly call the invoice in change mode.

Tried to create a transaction variant, and it dosent seem to help,

Copied the transaction to a custom one and changed the activity type to change, I get a message "Transaction ZMIR4 does not exist in table T169' which i understand is the config table for all MM transactions. Please let me know if there is any way to reach the required functionality without adding any entries to the table T169.

Regards,

Srihari