How to convert in PDF/A in command line?

Hi !

How to convert in PDF/A through command lines the following extensions:
pdf
msg
xlsx
docx
pptx

I have tried the following command with no success:

`>> cd pathtopdfcreatorprogramfiles

pdfcreator.exe /IF"C:\Users\a\Desktop\TEST\FichierPDF_Test.pdf" /OF"S:\TEST\folderrr\pdfinpdfa.pdf" /OutputSubFormat"PDF/A-1b"`

It just opens PDFCreator and does nothing else, no file is created.

I am using the free version of PDF Creator v3.1.2

What am I missing ?
Maybe you have an idea @Robin.W @Frank ?