Is there a way to use a filter string with the IF function?
I have a spreadsheet that looks like this:

Invoice No.    Invoice Date    Invoice Currency    Invoice Value
1                       dd/mm/yyyy        USD                1234.56
65                     dd/mm/yyyy        USD                2345.67
74                     dd/mm/yyyy        EUR                3456.78
88                     dd/mm/yyyy        USD                4567.89

when I filter on the currency: is there a function such as
if(filter_string="USD";TRUE;FALSE)???

Thanks
Aref