Create a private key and a self signed certificate as explained in the Creating a Private Key and Self Signed Certificate.
The following is the syntax:
> makekeys -req [-v] [-password <password>] -dname <distinguished-name-string> <private-key-file> <public-key-cert><cert-request-file>
For example,
> makekeys -req -dname "CN=Symbian Foundation Developer O=Symbian Foundation C=GB" HelloWorld.key HelloWorld.cer HelloWorldreq.p10
Here, the -dname provides a simple distinguished name string to the MakeKeys tool. HelloWorld.key is the private key file and HelloWorld.cer is the public key self-signed certificate file that were created previously using MakeKeys. Helloworldreq.p10 is the name of the output certificate request file.