Inject parameters to BuildRunnerContext

Hi all,
I'm developing a new RunType.
In my plugin there are an Administration section that allows to set global settings and a RunType section that allows to create new build step in a build configuration.
I want send at agent the runtime parameters and plugin administration global settings, but if the settings change i want change administration parameters for all build configuration saved.

For example:
___________________________________________________________

Administration -> My Plugin

     MY GLOBAL SETTINGS
     ----------------------------------------------

     FILE PATH :    DIR\file.ps1  


Build step saved with my plugin runtype

     [STEP 1\1] Running file "DIR\file.ps1"   

__________________________________________________________ A user changes plugin global settings

Administration -> My Plugin

     MY GLOBAL SETTINGS
     ----------------------------------------------

     FILE PATH :    DIR\DIR2\file.ps1   

The build step must has the new parameter value

     [STEP 1\1] Running file "DIR\DIR2\file.ps1 "  


The BuildStartContextProcessor allows to ovveride parameters on build start, but i don't want send parameters for all build, just for build that contains my RunType.
How can I do?

Regards,
Danny