No prob, see below.
90 is the max value from every 3rd column so I need to return Week4
[TABLE="width: 832"]
<colgroup><col width="64" span="13" style="width:48pt"> </colgroup><tbody>[TR]
[TD="class: xl64, width: 64"][/TD]
[TD="class: xl63, width: 64"]Week1[/TD]
[TD="class: xl63, width: 64"]Week2[/TD]
[TD="class: xl63, width: 64"]Week3[/TD]
[TD="class: xl63, width: 64"]Week4[/TD]
[TD="class: xl63, width: 64"]Week5[/TD]
[TD="class: xl63, width: 64"]Week6[/TD]
[TD="class: xl63, width: 64"]Week7[/TD]
[TD="class: xl63, width: 64"]Week8[/TD]
[TD="class: xl63, width: 64"]Week9[/TD]
[TD="class: xl63, width: 64"]Week10[/TD]
[TD="class: xl63, width: 64"]Week11[/TD]
[TD="class: xl63, width: 64"]Week12[/TD]
[/TR]
[TR]
[TD="class: xl64"][/TD]
[TD="class: xl63"]50[/TD]
[TD="class: xl63"]57[/TD]
[TD="class: xl63"]60[/TD]
[TD="class: xl63"]90[/TD]
[TD="class: xl63"]95[/TD]
[TD="class: xl63"]137[/TD]
[TD="class: xl63"]60[/TD]
[TD="class: xl63"]44[/TD]
[TD="class: xl63"]26[/TD]
[TD="class: xl63"]49[/TD]
[TD="class: xl63"]51[/TD]
[TD="class: xl63"]38[/TD]
[/TR]
[TR]
[TD="class: xl64"][/TD]
[TD="class: xl63"]1[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"]1[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"]1[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"]1[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[/TR]
[TR]
[TD="class: xl64"]Result =[/TD]
[TD="class: xl63"]Week 4[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"]MAX[/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[TD="class: xl63"] [/TD]
[/TR]
</tbody>[/TABLE]