Not really. "Ha en hyggelig helg!" would be a good translation if you had spelled it correctly. "God helg!" is way more common, but the correctly spelled version of your answer doesn't sound clunky at all.
'Ha en' would be literally translated as 'have a' so im no expert but i would assume 'ha en god helg ' would be the correct direct translation of 'have a good weekend' considering 'god helg' would be short hand however may be more commen.