Hey @ChanuteJo,
If you want to use cookie value as a segment -
If you're using Adobe Launch Tag Manager you can create a data element to capture a cookie and send it to Adobe Target as an Mbox/profile parameter basis your requirement. Furthermore, you can use this parameter to create an audience and use it in an activity setup.
If you want to display value from cookies -
If you want to display a value from a cookie on the page, it can be done directly through the custom code option in VEC/FEC.
Hope this helps. Please do let me know if you have any further queries.