Distinctive Ring

I have a sangoma card with two FXO ports… one of the FXO ports is hooked to a line with a distinctive ring pattern on it…

I know the pattern 391,347,340

I need to make the box NOT answer that line when it sees that pattern… is is hooked to a fax machine… so incomming calls on that pattern will always be for the fax machine.
Can someone help me with this?