I would like to use generic expressions in href file paths. For example in the following example: <mapref href="source_files_english.ditamap"/>, instead of "english", I would like to have something like <mapref href="source_files_"language".ditamap"/>. Then, i would like to define the word language as a key. So basically, what I have in mind is to use something like a keyref inside the href filepath. I tried: <mapref href="source_files_<keyword keyref="language"/>.ditamap"/>. Of course it did not work. Is there a way to achieve this in dita/xml?