(There may be a better way, but I never found it)
These instructions also cover rebus puzzles, et. al. (see pages 6-9):http://www.litsoft.com/across/docs/AcrossTextFormat.pdf
For any CC8 users who haven't yet encountered this issue, Crossword Compiler 8 supports circles-in-squares when creating a puzzle but it cannot export those circles to Across Lite/,puz format -- the circles are lost in the export.
I've only been able to create puzzles with circles-in-squares for Across Lite using this method:
- Export the clues and puzzle from CC8 to plain text
- Manually create a text file according to the instructions in the pdf above
- Open the txt file in Across Lite, and save as puz format
Maybe this will help someone else (I suffered a bit to get to a solution).