systemfunc_ncl reading nc files

[Chang]

Dear all,

I am trying to readingsome netcdf files. These files names are 191001_20191015, 191001_20191016, ... 191001_20191029.
When I code files = systemfunc("ls "+diri+"191001_201910[15:29].nc")
It will print 191001_20191010, 191001_20191011, ... 191001_20191029.
So please help me how to choose the files from number 15 to 29.

Thank you very much!
Chang