Thank you for your reply Micha,

"Do you use an official file provided by the total station (e.g. a GSI file from Leica) to import your data or do you organise the date in simple ASCII files?"

I wanted to import the raw data in GSI format but it didn't work (nothing happened) so I created a text file where I copied the data.

"Does each set of directions have its own group (an individual item in the tree menu)?"

I have a file for the zenithal angles, another for the horizontal angles and a last for the distances. So one file only per group of mesurement type in the tree menu.

"...depending on your task/project, select the desired point types."

Ok so I tried to use the datum points but it could not invert the normal equation matrix.

Thank you for your help,
Edoo.