Changing Home page

Question

Hi, Can I keep q2a in the same directory and change the first page to a completely new and different html page? 

for example my site it on mysite.com, I want when I goes to mysite.com, to see a home page that is different from q2a script, but the question stay on mysite.com/1,2,3....

Comments

Like sarthaks.com  right

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Yes, for the main page, but for the question and answer pages, they put them in "qa" directory and I want to keep them link "mysite.com/120"
because I think that Changing directory affects badly the site on google results

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It seems that I have 2 choices:
1- to change the directory of q2a to mysite.com/qa
2- to redirect the mysite.com to mysite.com/home.html
which one is better?