Dial any extension during voicemail greeting possible?

Hello. I know that during a voicemail greeting a caller can press 0 to jump to the o extension or * to jump to the a extension, but is there a way for a caller to be able to press any extension to jump to that extension? For example, during a voicemail greeting I want a caller to be able to press 800 to jump to the 800 extension. Is that possible? Thanks!

I ended up using the Background() application to play the voicemail greeting then have the Voicemail app run immediately after without specifying u or b in the options which takes the caller right into the instructions to leave a voicemail.

Set the ‘jump’ extension to take the caller to the directory.