My husband signed papers with a power of attorney for me. The main thing that Disney is looking for, as you already stated, is that the POA indicates that it is specific for the
DVC purchase. I just used the standard NY durable general POA form (which is available here:
http://www.nylawfund.org/pubs/durpoa.pdf). (I know it should have been a nondurable one, but is was my husband and I trust him!). This was the POA form that my company's closing attorneys had (they're right next door, I'm in the mortgage business).
I filled it out myself (it's self explanatory, hey, if I don't know how to fill out my name and address... that's really all there was to it!). I gave authority for "(A) real estate transactions" and ("O) all other matters" and wrote in at (Q) "for the specific purpose of purchasing a timeshare period from the Disney Vacation Club". The form had to be signed and notarized by me and my husband (the appointed agent). I had to fax it to Disney for their approval (which, obviously, it was acceptable). When it came time for signing the documents, Disney, of course needed the original, as it will be recorded with the Clerk's Office along with the other papers. My husband had to sign my name and write "by [mle's husband] as Attorney-in-Fact for [mle]" at each an spot where my signature was required.
All in all, it was costless and painless and enabled this NYer to buy at BCV.
Hope this was helpful. -mle