I can do something similar to what you asked for, let's see if you can.
Assuming the following table:
+------------+---------+
| Vendedores | Mês-Ano |
+------------+---------+
| João | jan/14 |
+------------+---------+
| João | fev/14 |
+------------+---------+
| Antonio | jan/14 |
+------------+---------+
| Antonio | fev/14 |
+------------+---------+
| Paulo | jan/14 |
+------------+---------+
| Paulo | fev/14 |
+------------+---------+
| Carlos | jan/14 |
+------------+---------+
| Carlos | fev/14 |
+------------+---------+
Click the Insert tab, and then click PivotTable:
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ItwillopenawindowaskingfortherangesofdatatobeusedwhencreatingthisPivotTable,usuallyExcelitselfalreadyautomaticallyselectstheentiretable,ifithasnotselected,selecttherangeofdatayouwanttouse.ClickOk.
Anewtabwillbecreated.DragthesellerfieldtoColumnLabelsanddragtheMonth-YeartoLineLabels,asshownbelow:
A table like this will be created:
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Noticethebuttonwithalittlecell-sidecolumnlabels,ifyouclickonit,youcanchoosewhichsellersyouwanttoshowinthePivotTable:
Finally, once the sellers are chosen, copy the table and paste As Value into some new worksheet because the PivotTable is read-only.