Speed dial voicemail box with pin code included?


I’ve got a speed dial button setup to access a dummy extensions mailbox, i want to add a pin to that mailbox to keep it secure but include that pin on the speed dial button so that certain phones don’t need to enter it manually.

I’ve got *98599 to dial the mailbox for 599, tried *98599,1111 for example, but to no avail. Anyone know what i need between the pin and the mailbox number for it to take the passcode?