In your root .htaccess:
redirect 307 index.html click here
At the top of .htaccess, if not already present:
That first line sets a temporary redirect from any request for the root index file (suffix is not important in this instance) to the data sub-directory. The second code allows htaccess mods to work.
Search for corz.org or askapache.com for good guides. Change the number to 301 if you want to indicate a permanent redirect.
Caveat: htaccess tricks almost always work fine with almost every Apache server. But if doesn't, ask your host.