Add more gag sounds to zaz gags?

[hodni]

Hi, so basically just wanted to ask how to add more sounds to Zaz's gags? 
i tried just dropping new files into the designated  folders but it wont play them.
for example:
default files are
Frustrated 01
Frustrated 02
Frustrated 03

I added new ones and named them Frustrated 04 and onwards but those new files didnt play

any help would appreciated

[donttouchmethere]

Check out how they did it here: