As I read the question, you're working in your web browser and you want to move the URL (address) of the page you're looking at into a different window or tab. This may vary slightly depending on what web browser you're using, but in Firefox I find that if I left-click anywhere within the address bar, the entire URL is highlighted. If that doesn't work for you, just put your cursor directly to the left of the first character of the URL, hold down the left mouse button, and move the cursor to the right until the entire URL is highlighted. Once you have the address highlighted, put your cursor over it, right-click, and a menu opens that should include a 'Copy' command. Left-click on that. Now place your cursor in the address bar of the window or tab where you want that URL to be and right-click again, and the menu that opens should include a 'Paste' command. Left click on that and you're done. You can probably also find the copy and paste commands under the 'Edit' menu of your web browser, and if it's easier you can use those rather than the pop-up menus I described.
If you still have problems, or if I'm missing the boat on what you're trying to do, please post again.