How to convert directories with BMP files with recursion
This is Sample4.bat contents:
Bmp2PDFPilot.exe /A /R "Sample files" /O "Sample PDF files\Sample4.pdf" 
Files list to convert:
All BMP files from directory "Sample files" and it subdirectories
Used required switches:
/O - required switch. Here it tells program create PDF file "Sample4.pdf" in "Sample PDF files" directory
Used not required switches:
/A - auto open 
/R - search for files recursively
Program create PDF file Sample4.pdf in directory "Sample PDF files" 
from bmp images located in directory "Sample files".
All bmp images from subdirectories of "Sample files" will be included recursively.
If output directory does not exist, it will be created
When converting process is complete,PDF file "Sample4.pdf" will be opened.