There are others on this board much more aware of this than I, but basics as I understand them are:

For Star Alliance you would have needed to given your United number to Singapore to earn miles in a United account. I do not believe there is any way to transfer miles for status.

As far as transfering to another program Hilton Honors allows you to transfer many airlines miles into Honors then you can transfer Honors points to airline miles on another carrier. However you lose a lot of miles in the process.