You best bet would be to use a programmatic approach, as Paul suggested. That way, by adding the receiver directly on the SPEventReceiverDefinitionCollection from the EventReceivers property on an SPList object. Just notice that since you added your receiver programmatically you will need to perform manual cleanup too.
I also would point out that AFAIK you should be able to do the same with a caml only declaration by referencing the resource SharePoint uses for the page library name.
<UrlAction Url="$Resources:osrvcore,List_Pages_UrlName;/SomePage.aspx" />
This example is taken from one of my old questions. In this case I am setting the UrlAction url but you should be able to use this format even with the ListUrl.
There is a big problem though. This sample does not play well with the MUI support: SharePoint will resolve the url based on the UI culture and not the original site culture. That means that if the site has been created in English, the page lib will be Pages: now if you use the MUI support to show the site in Portuguese, SharePoint will resolve the resource as Paginas, thus creating problems in your custom action. As I said, this is based on my experience with the urlaction param, but I would expect that ListUrl behaves the same. My advice: use code.
(note: If use a code only approach, please accept Paul answer. I am posting this only to leave a reference of the MUI problem - Would have used comments but it is a bit long as you see)