Not 64 bit problem.
Great difficulty solved problem.
The target must be complete file path.
Otherwise, not will create.
(command "shell"
(strcat "d:/gs32/gs9.18/bin/gswin32 -dSAFER -dBATCH -dNOPAUSE -q -iDirectories=d:/gs32/gs9.18/bin
-sDEVICE=pdfwrite -sOutputFile=d:/gs32/gs9.18/bin/target.pdf a.pdf b.pdf ")
)