In the services parameter there is a setting called " Always display original dialed number" set to true so that when someone calls your desk phone it will only display that number and not what ever you have it forwaded to.
Below are the remote destiation instuctions
Step 1.-Configure a Remote Destination Profile
Go to the Cisco Unified Communications Manager Administration page
Select Device Settings
Select Remote Destination Profile
Select and Click the Add New button
Configure the following settings
Name: mobilityuser_RDP
Description: Mobilityuser Remote Destination Profile
User ID: [your mobility user]
Device Pool: [an appropriate device pool]
Calling Search Space: [an appropriate CSS]
User Hold Audio Source: [your option of preference]
Network Hold MOH Audio Source: [your option of preference]
Privacy: [off]
Rerouting Calling Search: [preferably a CSS that have access to the pstn] *although I will suggest you to configure an special CSS for mobility to avoid fraud
Calling Party Transformation CSS: [none]
Leave all the rest as default
Select Save
Proceed to a new DN by clicking on the Line[1] – Add a new DN link
For this example I have created DN 0621, and it's the same DN that I am using in the Cisco 7961 IP Phone that I created above, so by entering the DN and selecting the a partition it should auto populate
-Click Save
Step 2.- Create a new Remote Destination
Go to the Cisco Unified Communications Manager Administration page
Select Device
Select Remote Destination
Click the Add New button
Enter the following Settings
Name: mobilityuser_mobilephone
Destination Number: 9+[mobile phone number] (please refer to your dialplan)
Answer too Soon Timer: leave as default
Answer too Late Timer: leave as default
Delay Before Ringing Timer: leave as default
Remote Destination Profile:[select the newly created remote destination profile]
Select the mobile phone check box
Click Save
Next select the Line association check box and click Save
You may need to reset the phone that is associated with the mobile connect user
Your user is now ready to begin using the mobile connect feature
To send call to Mobile Phone and the call will sent to his/her mobile phone, to reverse back to his/her Cisco IP phone he/she will need to simply hang up their mobile phone
Hope this helps.