Adding Dokuwiki to a Squarespace site

What would be the best way to do this so that the domain stays the same in a user's address bar.  Domain.com/wiki redirecting to another server?  Or am I being too complicated and I could just upload the dokuwiki files to a subfolder on the squarespace server and it would work the normal way?  Does Squarespace have PHP?

To point to another server domain.com/wiki would need to redirect to a subdomain like wiki.domain.com or any other domain. 

Squarespace doesn't have PHP.

Neither does it have the ability to upload files in a folder structure - allfile uploads end up in a /s/ directory. 

If you enable developer mode you can overcome the folder structure problem but you still couldn't use PHP.