Start reading at a specific index?

[ToddAndMargo via perl6-users]

Hi All,

Is there a way to modify this to start reading at
a specific index?  And include how many bytes (3000000)
to read as well?

     my $FileHandle     = open( $FileName, :bin, :ro );
     my Buf $BinaryFile = $FileHandle.read( 3000000 );

Many thanks,
-T