Making changes to a Excel xls file

Hi ;
This is an eazy one.....

I am a programmer but never have programmed excel and want to know if there is ay Web-based onlie help that would allow me to write the following functionalities to a (Macro ???) or a VB(???) to read an XLS file and do
1-Delete a Column
2-Reformat date column(s) from whatever to say yyyy-mm-dd
3-Reformat Time column(s) from whatever to say hh.mm.ss
4-write the output into a CSV file..

I guess it is easier to write a macro to do all that rather than using VB ...Am i right?

Thank you