Solved it with a bit of manual work and IE browser. Here's roughly how:
- export to csv file
- open csv file in IE
- change encoding in IE to Cyrillic
- copy back to a CSV file (requires some jumping through hoops to maintain the structure)
- prepare the file for import, e.g. remove unnecessary first and last lines, change semicolon to forward slash (not sure it was needed)
- use text file-tag function