Manual Dial and entering DTMF digits with Off Hook

Hello;
vicibox 4.0.3, vicidial 2.8-404a, Build 130605-0841, asterisk 1.4.39.1-vici, Single Machine, Vtiger 5.4
Because I do not need the agent to get out of the room in the Off Hook, I locked the keys at the IP Phone and I let all the dialing to be from the agent desktop screen. The problem that we are facing it currently that when they dial to bank or company (to PBX or IVR system) and they need to dial 1 or 2 or any the extension, they are not able to do this .. they do not know from where to press these DTMF digits as the Phone keypad is locked. Any help?
Regards
Bilal
vicibox 4.0.3, vicidial 2.8-404a, Build 130605-0841, asterisk 1.4.39.1-vici, Single Machine, Vtiger 5.4
Because I do not need the agent to get out of the room in the Off Hook, I locked the keys at the IP Phone and I let all the dialing to be from the agent desktop screen. The problem that we are facing it currently that when they dial to bank or company (to PBX or IVR system) and they need to dial 1 or 2 or any the extension, they are not able to do this .. they do not know from where to press these DTMF digits as the Phone keypad is locked. Any help?
Regards
Bilal