> I've a dynamic table tha have many radiobuttons and i need to click on a specific item. is there a way to click on a item by index number.
I haven't seen the overall page markup for the given table, but it is quite a common thing for dynamic pages that do not have unique and stable identifiers for web elements, to apply multi-steps approach to get and use required web element.
As a possible example for your case:
-- Assuming, that for the given table you are not looking for just the radio button, but looking for the radio button that is in the right-most column of some row, and another column of this row contains identifying information (e.g. order number),
-- You may search for this identifying information first;
-- Then, using the knowledge of how the page is designed, you should figure-out / calculate the row;
-- Then, for the found row you should find its right-most column and search for the radio button that is within the found cell. (Note, this well might be not a real cell with <TD> markup, but something, that looks like the cell but has different markup. <DIV>, for example.)
ACtually, ALL properties would be more useful than just the Extended properties. When searching for and identifying an object, there could be other properties of the object that can be used. FindChild and NameMapping don't only have to be restricted to the Extended Properties.
AlexKaras has a good suggestion as well. For some of our work, we use that approach, find a desired row by some other text and then target the Cell contents in that row.