iExpense policy setup

Hello,

I am trying to create a policy of 'no more than $100 per month allowed for Fuel'.

I have created Fuel expense item under Miscellaneous Expense category but I do not know how to assign the monthly limit.

In the iExpense setup responsibility where we define policies, there is the option of daily limits but I don't know how the monthly is achievable.

Thanks in advance for your help!

Susan