I have two files one has the data for world and another for US. and the data
points in both files are the amount and the number, this data is in turn for
a number of items like a,b,c.....

Now i want to club these two together and make a comparitive chart which
will be world and india amount in bar chart and no in line chart for the
different items a,b,c etc...

The problem here is not the charts but how to combine both of the data
points. This dataitems are from files who's name keep on changing according
to the date.

Is there something somebody can suggest..... there are many different files
in which this is to be run so.....

i was thinking of maybe making the chart just once and then looking up both
the values from the new files everytime but here the problem is that the file
name keeps changing..... so.......