There is no command to automatically copy caller phone number from an incoming call. However, there is a new feature in the RC app that allows user to launch an external app and passing along the caller number, full name, last name or first name. See the screenshot for more. Just turn on the " Launch an external app or a URL for incoming calls" option to see the setting dialog.
For click-to-dial, the easiest way is to implement the dial/call url scheme. I am not sure what you meant "from within a database". How do you access the database? If it's a web app, you can simply wrap a number around with this hyperlink:
<a target="_blank" href="rcapp://r/dialer?number=phone-number">Dial this number</a>
OR,
<a target="_blank" href="rcapp://r/call?number=phone-number">Call this number</a>
