Compare Data from different Data Source

[synaptics]

Hi, excuse me for my bad english. I have a problem whit two different data source.

I have a filed [Valore Acquisti] in a qlikview table from information system furthermore i have

three fieldname load from excel file (see below):

Fatturato da	Fatturato a	Contributo
0,00	250001,00	1,3
250001,01	9000001,00	3,2
9000001,01	1400001,00	3,9
1400001,01		5,4

I wish expression that when I sum([Valore Acquisti]) compare the value with the range of table and return corresponding data (Contributo)

P.S. attach the file jpeg qvw

Thanks in advanced for help me.