William I was having trouble holding the pinpoint button also. But reading through the manual I saw you can set the pinpoint up to be on or off . So all you have to do is hit the button once for on and then again to turn it off . This is referred to as pinpoint lock and can be found on page 50 of your CTX 30/30 instruction manual .
Hope this will be a little easier for you it is for me.
Ed B Diggin