You can do weight maps, but also goto into geometry tool setting, and see if the ponytail is a seperate block of geometry, a submesh. If so hide it by clicking the eye. Do your dforce and then unhide the tail. It should be where it orignally was. But something to keep in mind when dealing with dforce on objects with subs, is that you want to put the 0% influence on as much as possible otherwise it's probably going to get wonky.
Comments
Yes, apply a dForce weight map.
You can do weight maps, but also goto into geometry tool setting, and see if the ponytail is a seperate block of geometry, a submesh. If so hide it by clicking the eye. Do your dforce and then unhide the tail. It should be where it orignally was. But something to keep in mind when dealing with dforce on objects with subs, is that you want to put the 0% influence on as much as possible otherwise it's probably going to get wonky.
Redacted