Editing .htaccess for subdirectorys?
 

EDIT: I meant subdomain!

I have a main site, then I have a subdomain which is a mobile blog.
I want to edit the permalink structure for my blog, but I need to edit the HTaccess file. Problem is I don't see one in my domain. There is one in my main directory, but I"m scared it will screw up my main site... any ideas on how to do this?