Sorry, I'm still not sure I understand you. As far as I can tell from the results in the link you provided, you have various directories/subdomains which you are testing. If you place a robots.txt file in your root directory, blocking just these test directories, that won't affect your main domain.
Alternatively, you can add <meta name="robots" content="noindex, nofollow"> to all your test pages. (And remember to remove it when they go live. )