I have a decimal value i need varying places of precision to be displayed in the PDF i create using Reporting.  If the value is 1.3800, i need to display $1.38.  However, if the value is 1.3833, I need to display $1.38.  How can i format as currency AND yet allow the value to show up to four digits after the decimal, but also truncate to only 2 if the value contains the two trailing zeros?  Obviously I can't simply set the Label->Text->FormatString to c2, because this will not show the 3rd and 4th places if they are other than zero.  Basically I just need to truncate to 2 digits ONLY when the digits are not zeroes, and then show the $ sign etc.  I also need to show empty string if the value is equal to zero.  Here's what I have so far:

=If(Fields.CalcBillingRate<>0,(Format("${0}", Fields.CalcBillingRate)),"")

which works fine except it doesn't truncate the value to two places when the value is, for example, 2.0000 (should show $2.00)