[gentoo-user] emerge - pointing to local file

[Joseph]

Can someone refresh my memory how to emerge application pointing to local 
source file?
I need to re-emerge: asterisk-addons-1.4.7
but it does not seems to exist on any mirror (I have in may make.conf), I found asterisk-addons-1.4.7.tar.gz file but I need to point emerge to local file 
instead.

--
Joseph