How to include a file (INL.H)

Hi community,

we try to include a .h-file by using EXEC SQL INCLUDE INL;  SQLPP gives error message "E2619 include file not found"; we've also tried to use the -I option for SQLPP, but this option is not recognized (help page is displayed when invoking with  -I).

Version:  SQL Anywhere Embedded SQL Version 16.0.0.1948

Many thanks for Your help.