Out of OF tree addons

I'm wondering if it is possible to compile and run addons out of OF tree.
I would like to have something like :

 myaddons
    +ofxAddon1
       +src
       +example-addon1
    +ofxAddon2
 of_vRelease
 of_vNightly
 of_vPersonal

and be able to compile and run example-addon1 with the Release version of OF, the Nightly version and the Personal version.
Is there some way to add myaddons to the addons search path ?
Thanks