I don't think so. In reading the spec's on the Valcom v-2000a only loop current is supplied back to the phone system so if the access were dialed for a outside line access there'd be no battery for the system to think it were an outside line to access it.

Here's the statement on Valcom's site:

In connection with a telephone system, the unit shall have the ability to provide loop current to the system for access. In connection with a telephone system page port, a "dry" tip and ring connection shall be provided. A battery feed switch located on the unit shall turn loop current on or off to the tip and ring connections.


Here's the document

Retired phone dude