Welcome to FlyerTalk, and I wish you were joining under better circumstances. Regarding the disposition of any unused United Mileage Plus miles, please see the following thread:

http://www.flyertalk.com/forum/unite...ad-merged.html

I do appologize for any insensitivity in the thread title, as your father is still alive. I hope this is of help and again, I am very sorry to hear about your father's diagnosis.