As for import /export file what you can do is the following:
1- create any site with all needed database like site height, antenna types, frequencies, BSIC, CID, cell name…etc
2- all what you have to do export the site database (under file ) to txt, html…etc
open the file with word or excel (preferable excel), then build the remaining net. on the same file
so, as you can see it is a straight forward step.