How to access dynamically generated HTMLInputfile controls in Code behind

 Hi,
I am stuck in a problem if any one can help me out. I am using a server side function to generate html for HTMLInputFileControl. I append html in a string builder object in this way
sbHTML.AppendFormat("<tr><td style='padding-top:0px;'>{0}</td><td align='" & IIf(Not isArabic, "left", "right") & "'><input type='file' id='q_{2}_0' name='q_{2}_I' runat='server' size='{ ...