Where does the data come from before you process it with your VB script? Many data sources have the ability to create XLS files as their output, so it might be easiest to simply create the data in this form instead of writing a VB script to transform existing data into the Excel .XLS format.
Which version of DTS is running on your SQL Server? There are several flavors/generations of the DTS product, and each of them offers different opportunities and restrictions that will affect your choices.
Do you have the option of using SSIS instead of DTS? SSIS is a much more mature product than DTS was, and offers many more features.
In theory, theory and practice are identical. In practice, theory and practice are unrelated.