joelost – welcome to the forum.
When you enter a number into "Trusted Callers" your OBi changes all of its InboundCallRoutes (except the OBiTALK trunk) and will add a rule such as this, if using "Partial Match":
Voice Services -> SP1 Service -> X_InboundCallRoute
{(x.2331200):aa},{ph}
This means that a CallerID of none or any number of digits followed by 2331200 will be routed to your OBi Auto Attendant.
If you are happy to manually change the relevant InboundCallRoutes, then you could use a rule such as this:
{(40423312x.):aa},{ph}
This means that a CallerID of 40423312 followed by none or any number of digits will be routed to your OBi Auto Attendant.
In practice, as there may well be a "1" as the first digit of a CallerID, then this rule would cover various possibilities:
{(x.40423312x.):aa},{ph}
I'm sure that you get the idea!
Make changes via the OBi Expert Configuration pages. From your OBi Dashboard, click on your OBi number and follow the prompts to get there. To change a value uncheck both boxes to the right of the value and leave them unchecked. After changing the values on one page, press submit at the bottom of the page and wait a few minutes for the OBi to reboot. Then move on to the next page if required.