get_extra_cmt

Get extra comment line
     ea - linear address
     n  - number of line (0..MAX_ITEM_LINES)
          MAX_ITEM_LINES is defined in IDA.CFG
To get anterior  line #n use (E_PREV + n)
To get posterior line #n use (E_NEXT + n)
Returns number 0 if the comment line does not exit

string get_extra_cmt(long ea, long n);