Use the ItGetLine routine to access a specific row in a table:
void SAP_API ItGetLine(ITAB_H itab, unsigned line);
This routine returns the address of the lineth line in the internal table specified by the handle itab.
The ItGetLine function is only for reading table rows: you cannot update the data in the row. If you want to update table data, use the ItGupLine routine.
The corresponding ABAP operation isRead Table... Index...
This function is defined in SAPITAB.H.
handle of an internal table
number of the desired row, row numbers start with 1 similar than Sy-Tabix in ABAP