I forked the excel exporter on github and added functionality to parse your values with a microflow.
When you create your columns there is an option to choose a microflow now.
The microflow needs to have one string parameter and needs to return a string.
Here is an example:
Here is a link to the test project on github. You can export the module from that project.
I’ve submitted a pull request so its possible that this feature might be added.
Hope this helps!