reporting services - Looping in SSRS Report Tablix -

recently, im come across situation i've loop through each rows in tablix :

foreach(rows in tablix) {     //operation } 

but dont think possible.

so, possible loop through rows inside tablix?

my problem made me :

i've tablix column contains : first(rs!field) inside row group and, in last row outside group want sum(first(rs!field)), mean, want sum, first field each row group. not possible ssrs. cant sum sum(reportitems!textbox.value) inside tablix.

thats why come accorss situation.

i know there no solution above, why, thinking if there looping statement available.

i'd tried function code set , values :

public shared dim total double public function settotal(byref val) {     total=total+val }  public function gettotal()as double {     return total } 

but, way, if scroll pages forth , back, each time sum values existing.

hope understand. i've tried possible think.

so, please let me know, if there can achieve looping functionalities?

thank in advance.

i've added pictures :