dsp.AudioFileReader segment reading

Hello, I'm reading an mp3 file with dsp.AudioFileReader and I only want to read the segment from 1:20 to 1:60 (minute:seconds). ¿Do I have to read the file from the beginning and keep only the segment I want when I get there or is there any other way to do this? I was thinking maybe a seek() method to position the reader where i want it ot maybe passing a parameter to step() method.

thanks a lot