Thanks for the answer.
Yes, I see this script. I'll probably use it.
I found external_bases_ecp_examples.zip (probably from this forum or maybe from other one) with some .inp files.
Thus I decided to store non-standart basis sets and ECPs in separate files like in prep_example.inp but it didn't work, so I tried to compute prep_example.inp (of course, I've copied all the files needed) but I got "ERROR READING VARIABLE SCFAC".
What's wrong with using #libdir ./mydirectory in the beginning of file and @filename.bas for inserting basis for current atom?
Assume one has to use external basis (defined in basis.lib) for several atoms and build-in basis for other ones.
How to make correct .inp file?
Using $BASIS EXTFIL=.t. $END and basis names in $DATA group gives error.
Of course, it's possible to omit $BASIS group and just add all non-standard basis sets in $DATA group, but is this the only way?