How do i read the following file which has columns of data with header and space or tab delimited, in common lisp.

I also wanted to put the data in to list of list which contains rows.

Also how to get the difference in dates in common lisp

ID YR MO DA YrM MoM DaM  

100 2010 2 20 2010 8 30  

110 2010 4 30 2010 9 12  

112 2010 8 20 2010 10 20