A family of Microsoft word processing software products for creating web, email, and print documents.
Yes it is possible if the form used VBA macros. The document's format would have to be either "docm" or a "dotx" that was generated dynamically from a "dotm" attached template.
Selecting an Option from the Combo Box control would invoke a specific routine that was part of the ThisDocument class of the document or the attached template. The routine is:
Private Sub Document_ContentControlOnExit(ByVal ContentControl As ContentControl, Cancel As Boolean)
Based on what was selected from the Combo Box the other Text Content controls would be dynamically created. I would suggest placing those other controls in either an addressable table cell or a bookmark.
This is not a quick and easy solution and requires a fair amount of coding, so at least for me, I would only do it for a fee.
If you are interested, you can contact me using the email in my signature line.