Add File Upload to Page Creation Dialoge

Hi. How can I add a file upload field to the page creation dialog ?
I’d like to create new Pages from existing XML data.

I read that file uploads are not supported by standard, but i didn’t understood how to enabled it.

Currently, the list of supported field types in the dialog is limited to checkboxes, date, email, info, line, link, list, number, multiselect, radio, range, select, slug, tags, tel, text, toggles, time, url.

Thank you for support.

Christian