(((((((((((((((((((( wi ))))))))))))))))))
i know i've come into this late. i'm so sorry for the "hell" you're going thru. i applaud your wanting only what is best for your daughter.
about the computer, has there been a divorce with a separation agreement? if so, what does the agreement say about the computer? if it says nothing, i would do nothing (except clean it up in case i had to let go of it quickly). he could take you to court and let the judge decide. also, if divorce is pending, i would clean it up and still wait for judge to decide...unless, of course, you don't want another fight which i can SO understand.
however, if this has happened since the divorce and it was a loan, you'll have to return it and i think sending a letter explaining that you will, at a certain time in the near future, will suffice. make sure to keep a copy of the letter and send it to him certified mail. there's your intention should he decide to "play dirty". your request would be reasonable in the eyes of any authority, i would think.
this is just what i would do, based on my knowledge.
i wish you well and thinking of you and yours right now.
kd