Sounds like you're going to have to discuss the issues with an attorney to get a better idea of what your options are and what the procedures might be. I ran across this link online (with an appeal to all the appropriate disclaimers):

Finnish marital law:
http://www.pllaw.fi/family.htm

Finnish mental health service info:
http://www.ijic.org/publish/articles/000034/index.html

Finland site on child abduction (just a heads-up since you are dealing with international issues):
http://www.om.fi/18274.htm
http://www.om.fi/18271.htm
http://www.om.fi/18263.htm

MrsNOP - with many good wishes for you and your family.