How do I add additional languages to the sla.r I use with my .dmg?

I am using SLAs bundled with my DMGs as described here.

However, I want to support SLAs for languages (for example Catalan) beyond those given in the SLAResources file provided by Apple.

Is this possible?

From stackoverflow

• Yes. Add an entry for Catalan to the 'LPic' resource, and add matching 'TEXT' and 'STR#' resources using the resource ID you defined in the entry. You can use ResKnife, an open-source clone of ResEdit, to edit the file.

  The language codes are defined in /System/Library/Frameworks/CoreServices.framework/Frameworks/CarbonCore.framework/Headers/Script.h.