VS 2010 How to use cookie in a textbox

Hello everyone
i met a problem today
Now i have a string cookie in a textbox
such as
"__utma=266184461.1410363758.1376470306.1376499042.1377531968.3; __utmb=266184461.1.10.1377531968; __utmc=266184461; __utmz=266184461.1376470306.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); Hm_lvt_3d143f0a07b6487f65609d8411e5464f=1376461253,1377531968; Hm_lpvt_3d143f0a07b6487f65609d8411e5464f=1377531968"

and the domain is "http://www.scientific.net/"

Now i want to use it in Webbrowser or Httprequest

How can i use it?

thank you for your help