Settings that apply to all files in a specific folder are listed under the FOLDER tag, for example:
Windows:
[FOLDER:C:\\files\\acufiles] FILESUFFIX=dat [FOLDER:C:\\files\\rmfiles] IDXFORMAT=21
UNIX:
[FOLDER:usr/files/acufiles] FILESUFFIX=dat [FOLDER:C:/files/rmfiles] IDXFORMAT=21
sets all files in c:\files\acufiles (Windows) or usr/files/acufiles (UNIX) that do not have a suffix to .dat, and all indexed files in c:\files\rmfiles (Windows) or usr/files/rmfiles (UNIX) to an IDXFORMAT of 21.
[C:\SITETEST\EXTFH\TEST2.dat]
you would need to enter
[C:\\SITETEST\\EXTFH\\TEST2.dat]
This applies to Windows environments (local development) only.