How to calculated values on header

Suite and Optimus Suite 5
#1

How to calculated values on header :

$theorique = 100; //sql number

echo ’

Nombre de jours restant,#cspan,#cspan,".$theorique."-{#stat_total} ';

//stat_total result = 50

On the display :
100-50

Thx

#2

{#stat_total} renders us number only on client side. You should calculate number of rows on server side using PHP function and pass it as header label.

#3

Only my {#stat_total} change when i change value on my grid

Nombre de jours restant,#cspan,#cspan,100-{#stat_total}

I can’t do calcul with constant on header ?