It depends on what exactly you mean by "create a new entry".
To suggest a new place for the standards database, go to the Places tool (https://www.familysearch.org/research/places/) and click the "Suggest A New Place" link at the top left. To suggest a correction to an existing entry, type its name into the search box to go to its page, and then click the "Improve This Place" button.
To use an existing standard for the map pin, but with a different label for it for display, type the desired label into the place field on the conclusion, and click the top choice in the drop-down. It has a gray background and matches the text you typed.
The associated standard (i.e. the map pin location) will be the entity that was directly below the gray one.
Click the tiny triangle at the right to change the association (if there's more than one available).