There is no way to remove columns from the generated excel file - it exports all columns from the column table. The field names displayed in the excel file are the form field's name for developers. This is the value that is persisted in the DB as well. In order to have this behavior altered, select the name for developers of your Form control (from the designer) and alter the FormTextBox_C001 entry to something you will later recognize.
Adding custom export is possible. I can recommend you use the approach described in this blog post
. However instead of getting the form subscribers you will need to trigger an export. The way to get all form entries for a form is described in our documentation
. Regarding the export itself - there are abundant resources on the web on how to export a collection to the format you require.
Ivan D. Dimitrov
Do you want to have your say in the Sitefinity development roadmap? Do you want to know when a feature you requested is added or when a bug fixed? Explore the Telerik Sitefinity CMS Ideas&Feedback Portal
and vote to affect the priority of the items