Hi EGKK,
There is a rough guide at:
http://www.caac.gov.cn/dev/fbs/XJSYY...5529487025.pdf.
FCOM PER_LOD_WBA_LTS Load and TRIM Sheet, try moving your imaginary bags and passengers to see if you go outside the aft C of G limit. Obviously it won't tip on its tail until you are some way outside the envelope.