Question: how to create pfx file from crt and p7b?
Answer:  Copy your PKCS7.p7b file as PKCS7.crt.
 Open this file with your editor and add these lines. —–BEGIN CERTIFICATE—– ... 
 openssl pkcs7 -print_certs -in PKCS7.crt -out certificate.cer.
 openssl pkcs12 -export -in certificate.cer -inkey private.key -out PKCS7.pfx -certfile bundle.cer.