Symbols underlined like this can be typed with keyboard shortcuts. For example, to type €, press Alt + E; to type ¥, press Alt + Y.
Stop the mouse over a button to learn its shortcut.
Alt + click a button to copy a single character to the clipboard.
You can select text and press Ctrl + C to copy it to your document. In your target document, press Ctrl + V, or, if you want to paste the text without formatting, try Ctrl + Shift + V.