^You are (%d).(%a)~% of the way to becoming *.$ r_energy = %eval( %float( %concat( %1, ",", %2)) -@r_energy) r_session_nrj = %eval( %float( @r_session_nrj+@r_energy)) #SUBSTITUTE %line" ("@r_energy") ("@r_session_nrj")" r_energy = %eval( %float( %concat( %1, ",", %2))) (remeber to check use default value and set default value to zer0 for nrj)