I have thought of that solution.

But using a pronoun instead of SaH, is often done; e.g. "the sword is in the ocean" from tkd.

So, I think that choosing to ask by saying {qatlh pa' jIHnIS} or {qatlh pa' jIHnIStaH} is a valid option.

But I don't know which of the two is the correct choice.

I can't say that doing this is wrong, but it's not ideal. Daniel's response is better. The more meaning you try to load onto a pronoun, the more awkward it will be.

That said, if you have to say it this way — and you almost certainly don't — what you're really asking is whether you need to use -taH to indicate some kind of ongoingness or temporariness of your location. The answer is that we don't know. Okrand is inconsistent with his usage of this.

I prefer to use -taH when I'm talking about a movable object that may just happen to be somewhere at the moment, but not to use -taH when the object is fixed. vaS'a'Daq 'oH puchpa''e' 'ej puchpa'Daq ghaHtaH Qang'e'. But this is not an official rule and cannot be consistently demonstrated in the canon.

-- 
SuStel
http://trimboli.name