Well, for the translation of your questionnaire you don't really need Limesurvey to have Hausa. You could use e.g. English and then write the questionnaire in Hausa.
The only problem I see is that all the standard texts of Limesurvey would be in English then, just the questionnaire in Hausa. If you can live with that, you should be fine.
If not, you could create the language. The good thing about Limesurvey is, that it is open source and anyone can help.
I assume that you won't need the backend of Limesurvey to be in Hausa, but only the text elements that appear in the survey. Unfortunately the text files do not distinguish between this. I think I have mad a feature request some while ago, but I guess it was never considered: Having the texts for survey taking separated for survey creating/LS administration.
This way one could create a new language fairly quickly.
manual.limesurvey.org/Translating_LimeSurvey
translate.limesurvey.org/projects/
