Rolling 6 Months based on Month Selected

[#1]

Hi Dear QV Community

I have the "Rolling6Months.qvw" with a table info i need sum the last six months based on month selected.

Example: If I Select Nov 2012 The Second Expresion of Pivot table and TextObject make a sum of sales from Jun2012 to Nov 2012

Regular Expression: =Sum({<DescTarifa=>} [Vta Neta])

Please download the QVW attachement

[tresesco]

See it here attached.