I've solved this one before by generating a temp file, grabbing the absolute path, turning it into a url, assigning that to a property with the key "MAP_FILE" and then putting this in my main config: <sqlMap url="${MAP_FILE}"/>
Which resolves to: <sqlMap url="file://localhost/tmp/ibatis345875.xml"/> Or some such thing (the localhost bit seems to be required for windows but not for Unix flavours). Nice thing about this is that the generated file on disk is easy to debug, just log out the temp file location after generating it.