Exporing from command line with RSA Private Key instead of Private key

Hello,
I have been trying to export from command line with PKCS1 Private key instead of PKCS8 Private Key, as there is format difference but it doesn't recognize the pem file, is there anyway I can get around this issue.

Thanks

What version of Briefcase are you using? What version of Java are you using? How did you create the private key? What is the exact error you get? Can you attach the briefcase.log?