How can I using the report designed of VFP 7.0 disregards all detail lines in a COUNT of a value, if the value is not entered or is 0.

For example if in my detail of a report my lines are as follows:

Inv. No. Amount.
-------------------
1 100.00
2 200.00
3 0.00

A regular count of amount would result in 3, however I need it to exclude the 0.00 amount and display 2 as the result.