If you want to reflect it on the Panner (Inspector or MixConsole), then the only one way is to automate it.
Then you could use a Project Logical Editor. Something like:
(Media Type is | Equal | Automation | And
Container Type is | Equal | Event | And
Name | Contains | Standard Panner | And
Position | Inside Cycle | [i]keep Parameters 1 and 2 empty[/i] | [i]any settings here[/i] )
Trim | Multiple by | [i]your value[/i]
(Wow, the line “Name | Contains | Standard Panner | And” is actually really smart!!! …To make sure only Pan automation will be affected.)
See attached screenshot, please.
You could again prepare some presets with different Multiple/Divide by values and assign Key Commands.
Then you would always need to select the Audio event, hit P (Transport > Locators > Set Locators to Selection Range) and apply the Project Logical Editor Preset.
Of course, you can even make a macros, so by the Key Command you wouldn’t trigger just the preset, but you would trigger different macros. The 1st step would be always this “Set Locators to Selection Range” and the 2nd step would be the wanted Project Logical Editor Preset.