Alternate #url#

Hello,

I’ve searched and read this entire forum trying to figure out how to use a custom #url# but I still cant figure it out.

In my posts I use the excerpt to hold a URL. When I use #url#, I want it to use the link in my excerpt, not the link to my post. How can I make it so that my tweets look like this:

custom tweet text #url#

where #url# shortens the link in my excerpt instead of my post id. I have tried using custom_fields but I still cannot figure it out.

Thank you

http://ww.wp.xz.cn/extend/plugins/wp-to-twitter/