Change the announcement played by Meetme "I" optio

Hello

Do you have any idea how to change the announcement file which is played by “I” option of MeetMe command?
This “I” option is used like this.
exten => 1007,1,MeetMe(101|I)
Then, 101 is the conference room number which is configured on “meetme.conf”.
When a new user is joined or leaved, an announcement is played for another users who has been already joined by this option.

Thank you and Best Regards,
mizuki