My daughter was born in Alabama. I married her father after she was born. I joined the military and we divorced in Colorado. Our divorce and child support order is all in Colorado. I'm now stationed in Arkansas. I would like to change her last name to mine. I know her biofather will not consent. At what age, is she able to make that decision? What courts do I have to go through? Colorado-where the parenting agreement/support order is or our current state of residence?

She may decide when she turns 18 ( if the state she is living in at the time allows at 18)

Before that, you will need her bio fathers permission.

Is it possible to get it hyphenated; with my new husbands last name and her bio fathers last name? This being without his consent of course. I want her as she gets older to not feel excluded from the family due to her last name.

No, any legal name change will require her bio fathers approval.

But not sure where excluded is, with many women when they get married today not taking the husbands name, ( that is a dying custom) With that over 1/2 of marriages end in divorce thus more and more mixed marriages.

Fitting in, is a matter of how they are treated, not what name they have. And how you and others treat her name. If she things you don't like it, she won't like it. If she is taught to be proud of who she is, she will be.