Select blank cells used range rows and columns

[emina002]

Hi All,

Hope you can help me figure out how can I select used range rows and columns and paste the desired formula. Ok my problem selecting the blank cells(count of rows and columns not fixed)

On my sample workbook I attach here, rows occupied is until row 42 and columns on row 2(Col H) I just want to select B3 to H3 down to row 42(but then I just want to clear that used range of column and rows is not fix). Your help on what code should I used will be appreciate.