T19P - DSSKey as DTMF

Hi,

We have some Yealink T19P IP-Phones and I would like to ask if there is possibility to send DTMF using SoftKey. We have this funcion in Snom phones

We need that to open the the door (doorcom). Means someone make call the user pick up and via (pressing) softkey (with programmed DTMF ton) send a code (example: #1234) to open the door...

how can i do this?

J.