I have a UC520 setup as a key type system where incoming calls go to an ephone-dn mapped to the CO lines.  The phones all have the CO lines as buttons.  The customer wants the extension button to ring on the phones but not the CO line buttons.  They would still flash when calls come in.  They would have the option to answer the calls and put them on hold.

Here is an example of one of the phone configs:

ephone  7
device-security-mode none
video
mac-address 0026.99AB.ECC3
ephone-template 16
max-calls-per-button 2
username "ReceptionistOne" password 1234
type 504G
button  1:12 2:53 3:52 4:51

buttons 2, 3, and 4 are the CO lines.

If I change a button to 2m53 or 2s53, I lose the ability to pick up calls that are on hold.

Is this possible?