[FFmpeg-user] Float formatting in drawtext

Hey, seems to be an easy question, but I have been searching for the answer quite a while without success: If I perform a float calculation via text=%{expr\:whatever} is there any way to format the output the printf way? I know, the result could be converted to integer and be formatted via text=%{eif\:whatever\:d} but this is restricted to integer results. Wolfgang Hugemann