** IMPORTANT NOTE : You can only export your certificate *AFTER* it is issued and you've visited the collection link.
To export a stored code signing certificate from Firefox to a PFX file follow these steps :
Click the Tools menu, then Options, then the Advanced tab on the left side
Click the Certificates tab on the right, then the View Certificates button at the bottom
Click the Your Certificates tab, location *your* company name under the COMODO group, and left-click it, then click the Backup button at the bottom
Firefox will prompt for the name of the certificate file and you may save it anywhere you would like with any file name you would like .
The final step is to set a password for the PFX file -- DO NOT FORGET THAT PASSWORD!
The file is portable and can now be copied to any computer. Additional Note : Firefox will save the file with a .p12 extension – that’s OK! Just rename the file to .pfx if you would like but you can use it with any code signing tool regardless of the file's extension.