Seperate data and design-style in Excel
 

I need to develop a solution that will implement the following:
1. Get raw data from email\file (XML\Text\HTML) and display it in Excel
(seems doable)
2. Allow the user to change design\style of this Excel sheet and save this
template.
3. Future raw data of the same type will use the user's template from No. 2.

As I understand it, I need to somehow seperate the data values of this Excel
sheet from the design and styling.

Any Ideas?

Many thanks.