Refactor PHP code that outputs csv with formulas

I have some PHP code that is to create a table with formulas already in it to sum some columns. There seems to be a much more elegant way to do this than the code below. What are some refactorings or design patterns that could improve something like the code below?

<?
echo ",Current Milestone,Total Hours,Milestone 1 Hours,Milestone 2 Hours,Milestone 3 Hours\n";
$row = 2; 
$totSSRange = ""; 
foreach($departments as $dept){
    $deptStartRow = $row + 1;
    echo $dept['name']."\n";
    foreach($dept['modules'] as $module){
        $row++;
        echo $module['name'].','.$module['ms'].',=SUM(D'.$row.':F'.$row.'),'.$module['m1'].','.$module['m2'].','.$module['m3']."\n";
    }
    $deptSSRange = "C".$deptStartRow.":C".$row; 
    $totSSRange .= $deptSSRange.","; 
    $sumStr = "=SUM(".$deptSSRange.")"; 
    echo 'Sum,,'.$sumStr.','.str_replace("C","D",$sumStr).','.str_replace("C","E",$sumStr).','.str_replace("C","F",$sumStr)."\n\n";
    $row+=3; 
} 
$totSumStr = "\"=SUM(".$totSSRange.")\"";
echo 'Total,,'.$totSumStr.','.str_replace("C","D",$totSumStr).','.str_replace("C","E",$totSumStr).','.str_replace("C","F",$totSumStr);
?>