How to get the count on characteristics infoobject

Hi experts,

we have a requirement to create a report between two characteristics info objects.For example

In Cube,we have data for

Info object1 Info object2

C01 M01

C01 M02

In report,I want number of materials purchased by customer C01

Thatmeans,I want C01 = 2

I created a report with Infoobject1 in row and created a formula in column and used a formula varibale with replacement path for inforobject2 with reference as infoobject1,but after executing it shows X mark.

Can you please help me to how to create the report.

regards

Pradeep