Wind zone particle system exclusion possible? [shuriken]

Hi.

Is there a way to describe Wind Zone relationships between particle system and Zone? I want to exclude one particle system from one field but still be affected by another.

Example: 1 Spherical Wind Zone that attract some particles towards it's center and another Directional Wind Zone blowing leaves around. I can't get them to exclude each other. The Directional field will blow on both (since it doesn't have bounds), and the leaves that get trapped in the spherical radius will get affected by that force.

I can only include all Wind Zones for all particles that have external forces enabled.

Is there something like a Dynamic Relationship Editor (Maya) in Unity?

Or some way of scripting around this? All suggestions welcome

thanks