Sorry but I have to ask: what is the purpose of your wish here?
I ask because one of the values of Acrobat are to have fillable fields available in their documents that maintain the structure of the document. When you have a field in a Word document, the text wraps and destroys the documents structure. This can lead to pages running all over the place, lines being split that do not need to be split. AND, if you are trying to collect the answers, you cannot export the data.
So I have to ask: what was wrong with the original PDF questionnaire that makes you want to convert it into a Word document?
Also, please let us know what OS you're using (and what release it is)?
And what version of Acrobat you are using (and what release it is)?
And just in case, what version of Word you are using (and what release it is)?