Sort and chart multiple series from raw data using macros

Hello,

So I have 4 sets of data with 3 columns each. When exported from another program into xls format, I get 12 columns with Data, X, Y given for each of the 4 sets of data. All the sets have different date ranges with some overlap. The X column in each set is just a labeling scheme of the program to uniquely identify each Date and Y pair. For example,
Text X Y
6/26/2005 18 5133.94
6/27/2005 19 5221.65

The file is attached in a shrunken format.

I want a macros which will accurately pull the Text (Date) column and Y value for each set and make each set a series (therefore series 1, 2, 3, 4) in a chart of Date versus Y.

Seems easy, right? Each time I export from the program, I will have more dates and Y values. I want the macros to be able to automatically update the chart to expand the selection to include the new values. I am also having trouble charting the Date on the X axis because it is not in the correct format, and excel insists on calling whatever the first data is "0" and each subsequent date 1, 2, 3, 4. NOT serial date or whatever it needs to be to display a date (unless i chart as a line, not scatter).

Any help with the macros, or just getting the date issue solved would be very appreciated!
Thanks!