XL Lookup Function in Zoho Analytics

I have a sales table and a fee structure table. The fee structure table sets out a monthly charge based on the volume of sales for a given customer. So, for example, I have:

Fee Structure Table

Customer Name
Sales From
Sales To
Charge
Customer 1
0
250,000
5%
Customer 1
251,000
500,000
2.5%
Customer 2
0
250,000
4%
Customer 2
251,000
500,000
2%

I need to lookup the sum of sales for a given customer from the sales table for a given month, work out what range that value falls into in the fee structure table (above), and return that result by customer and month in a reports (tabular and graph).

in XL I can use a simple 'lookup' function similar to =$C10*lookup($C10,$V$3:$X$6,$X$3:$X$6). Does anyone have any idea how I can achieve the same in Zoho Analytics?

Customer Name	Sales From	Sales To	Charge
Customer 1	0	250,000	5%
Customer 1	251,000	500,000	2.5%
Customer 2	0	250,000	4%
Customer 2	251,000	500,000	2%