You try with the following code.I am not able to find out any error in your code.
import java.io.*;
class
test {
static String s= "c:/Program Files/Microsoft Office//Office/EXCEL.exe D:/myfile.xls";
test()
{
try{
Process proc = Runtime.getRuntime ().exec(s);
}catch(Exception Ex){Ex.printStackTrace();}
}
public static void main(String a[])
{
new test();
}
}