The Structure spreadsheet file format (with extension .TXT) is used to import a Structure model in text format.
Open the binary Structure (STR) file from disk. (Use any file, or one from the Examples or Demos folder.)
Execute File | Export and save the file as a template file (in .TXT format).
Open the (.TXT) template file in a spreadsheet program like Microsoft Excel or a word processor like Microsoft Word.
Replace the Structure data (Point coordinates and optionally Lines & Surfaces) in the spreadsheet columns with your data.
Edit the other information where applicable, and save the file to disk.
.TXT File In Excel Spreadsheet.
Make sure that the (.TXT) file is no longer open in the spreadsheet or word processor program.
Execute File | Import | Structure and import the (.TXT) file into a Structure file.