my ($rest,$imc);
for my $i (0..$Groups+1) {
  for my $j (15*($i+1)-$Conds..15*($i+1)) {
    $avg->Range(xl_rowcol_to_cell($j-1,2*$Meas+5))->Select();
    $rest = 2*$Meas+4;
    $imc  = 2*$Meas+3;
    $Xl->ActiveCell->{Value} = "=ABS(RC[-$rest]-RC[-$imc])";
    $avg->Range(xl_rowcol_to_cell($j-1,2*$Meas+6))->Select();
    $rest = 2*$Meas+3;
    $imc  = 2*$Meas+2;
    $Xl->ActiveCell->{Value} = "=Abs(RC[-$rest]-RC[-$imc])";
    if($i == 0) {
      $avg->Range(xl_rowcol_to_cell($j-1,2*$Meas+7))->Select();
      $rest = 2*$Meas+2;
      $imc  = 2*$Meas+1;
      $Xl->ActiveCell->{Value} = "=Abs(RC[-$rest]-RC[-$imc])";
      }
    }
  }