Dear Junyi,
A similar question has been asked before–see e.g. the forum topic found here: NWTC Design Codes - General Questions. Unfortunately, we have not yet been budgeted the time to upgrade our internal RunIEC script enough to support its public distribution.
There is a simple MS DOS script provided with FAST v8 named “CertTest.bat” that we use to run the 26 certification tests. Another option is to start with the MATLAB scripts available in the FAST v8 archive used to read and write FAST input files. You could probably start with these and modify them to suite your needs.
Best regards,