When you load from Excel or any source, QlikView list all field header, in case of excel this are the column name.
Your question is about finding the row number of the header. In qlikview even if there are blank rows in excel and the first row that the headers starts from is say row 5, qlikview will not show or list blank rows from row 1 - row 4. QlikView will load the row header and ignore the blank rows.
May be more detailed explanation of your question might help.