Thank you all for your input, I finally got it to work by doing
set matchid .... set board .... rollout =1 =2 export position text Position_01.txt
The following approach still doesn't work: In the GUI, load a match and analyze highlight interesting move in the move list window by mouse-click in the command window, enter hint rollout =1 =2 (rollout then starts in hint window) export position text Position_01.txt
and then Position_01.txt looks like this:
Date: Juni 05, 2007 Move number 2: O to play 21
GNU Backgammon Position ID: 4HPkASjgc/ABMA Match ID : MAFlAAAAAAAA +-1--2--3--4--5--6-------7--8--9-10-11-12-+ O: mastino75 | X X O | | O X | 0 points | O | | O X | Rolled 21 | O | | O X | | O | | X | | O | | | | |BAR| |^ 3 point match (Cube: 1) | X | | O | | X | | O | | X | | X O | | O X | | X O | | O X | | X X O | 0 points +24-23-22-21-20-19------18-17-16-15-14-13-+ X: GGraccoon Pip counts: O 167, X 164