Export Surface Points To File dialog box
Opens via: TINEXPORT command
The Export Surface Points To File dialog box allows you to choose which surface to export.

Select surface
Allows you to select a TIN surface available in the drop-down list or pick a TIN surface from the drawing.
Format
Allows you to select a file format from the drop-down list or configure a new file format in the Manage Surface File Formats dialog box, which opens when you press the three dots from the right side.
File name
Allows you to specify the file's name and the folder where you want the TIN surface to be exported.