[Asterisk-Users] extensions and regular expressions ( probably an easy question )

[Sean Kennedy]

Hi all,

I'm having a hard time finding information related to the regular 
expressions that can be used in a dialplan, specifically as an 
extension.  For example, I have an 800 number which I'd like to jump 
directly to if my users dial it, instead of going over my pstn 
termination.  Currently, it looks like this:

exten => 8661234567,1,Goto(800-in)

However, I'd like 1866123456 to match as well.  I can't find in the wiki 
or sample configs how to say "match this 0 or 1 times". 

Can anybody provide a link that would go over this?  Again, I've been 
digging through the wiki, but I seem to be missing it.

Thanks

Sean