If you use Chrome, you might find this to be a handy extension:
https://chrome.google.com/extensions/detail/ghipmampnddcpdlppkkamoankmkmc...
The extension's options allow you to pre-fill all the things you may
want to enter (lang for syntax highlighting, post expiration/exposure,
post name/title, subdomain, and email) as well as override any of those
defaults on a post-by-post basis.
After posting, it will give you the URL and a convenient button to copy
it for quick pasting into the #rhq channel. I've set my subdomain to
"rhq" so that URLs are generated like
http://rhq.pastebin.com/GqgWqPZ3
-joseph