There is a script in Poser 5 or 6 and later called Convert to Universal pose listed in the Script menu... you could try that... I find it is best to just apply a pose. fix it by hand and then save... this really isn't too bad esp. with  figures that share the same rigging (e.g. breasts on chest v. breasts on collars) and more or less the same proportions (adult v. child)...