[docbook-apps] Page numbers in body.margin.outer

[Claudio Tubertini]

I would like to put the page number (in chapters or articles) in the
body.margin.outer (I believe this is the correct parameter, but I'm not
sure), in the middle of the page, instead of usual place in footer or
header. Can someone suggest me where to look for? I'm using FOP processor
with Oxygen.
Regards
Claudio Tubertini