<<I have always had an online related fantasy, that a dominant woman would command me over the internet to perform all sorts of humiliating, painful, or erotic tasks...>>
This sure doesn't have to be just a fantasy; in fact we do this all the time when Sylvie travels without me.
We use a webcam setup on her laptop, and she has to do exactly what I tell her to do. It's a great temptation for her to 'slip' a little bit, or 'forget' some instruction I have given her, but that just means her behavior has to be corrected when she gets home ... I thought it would be pointless; 'cause face it, if she doesn't want to sleep with handcuffs on, I can't do much about it from 1,000 miles away, but it works much better than I thought it would.
Go for it! Find an on-line dom, get to know them, and see where it takes you.
Amanda