I have never used the the Setup Room when creating a figure, and don't know much about it. I can't see a way to fix this in the Setup Room, or in any other part of the Poser interface. Personally I would save the figure, then edit the 'endPoint' line in a cr2 editor, or text editor. The 'endPoint' line contains three values seperated by spaces, the values represent the x, y, z, position respectively of the endPoint. You could Copy & Paste the endPoint for the head from the target figure to the hair figure.

endPoint 0 0.72836 0.0267356

x y z