"You are standing behind me."
Translation:jIH 'emDaq bIQamtaH SoH.
Da- is used when the verb has a direct third-person object. That is, when the action of the verb is on him/her/it/them. When the verb isn't done to anyone or thing, use bI- the prefix for a second person singular subject (you) with no object.
Your question is understandable, but I would have:
used Sa- instead of qa- -- as there are lots of readers here, you're not addressing just one
not used -lu'. I think you're trying to distance yourself from the foolish, but there is a particular thing you think might be foolish.
put the object-verb-subject of any sentence AFTER the locationDaq.
used wI- the prefix to use with a first person plural subject and a third person singular object, instead of ma-, which implies no object. That's exactly the same issue as the one your question is about, so maybe with your question answered, you would have corrected that one on your own.