Overwrite original tab

Hello
I'm creating a personal plugin that should display new tabs with custom fields inside..
Well i've created the tabs, added fields to them and now i would display fields filtered by some conditions

i've tried to create the list of fields using "getDisplayTab" function in my tab class

but seems it's just a function that "add" some html code to the tab...doesn't replace the original one

for example, if i assign "fooField" to "fooTab" in admin backend and i call it by getDisplayTab , it will be showed 2 times... ( i think first by the plugin and then by main cbTabHandler )

So how can i overwrite the original output and show only personal getDisplayTab output?

thank you in advance

actually i've solved modifying generateViewTabsContent on comprofiler.class.php

let me know if there is a smooth way please