Hi

We can use the al and sn tool to do the delay sign.
Use the sn -p to extract the publickey only,
use the al tool to delay sign the dll.
And use the sn -R to resign the dll.

Here is some information for your reference.

Obtaining the Public Key
To delay sign an assembly, you must have access to the public key. You can
either obtain the real public key from the organization in your company
that will do the eventual signing, or create a public key using the Strong
Name Tool (Sn.exe).

The following Sn.exe command creates a test public/private key pair and
saves it in the file TestKeyPair.snk. The ¨Ck option specifies to Sn.exe to
create a new key pair and save it in the specified file.

sn ¨Ck TestKeyPair.snk
You can extract the public key from the file containing the test key pair.
The following command extracts the public key from TestKeyPair.snk and
saves it in PublicKey.snk.

sn ¨Cp TestKeyPair.snk PublicKey.snk
Delay Signing an Assembly
Once you have obtained or created the public key, use the Assembly Linker
(Al.exe) to compile the assembly and specify delayed signing.

The following Al.exe command creates a strong-named satellite assembly for
the application MyApp from the strings.ja.resources file.

al /t:lib /embed:strings.ja.resources /culture:ja /out:MyApp.resources.dll
/delay+ /keyfile:PublicKey.snk
The /delay+ option specifies to delay sign the assembly. The /keyfile:
option specifies the name of the key file containing the public key to use
to delay sign the assembly.

For more information on delayed signing, see Delay Signing an Assembly.

Note that strong-named assemblies contain version information that the
runtime uses to determine which assembly to use to meet a binding request.
For more information on this topic, see Assembly Versioning.

Re-signing an Assembly
At some later date, a delay-signed satellite assembly must be re-signed
with the real key pair. You can do this using Sn.exe.

The following Sn.exe command signs MyApp.resources.dll with the real key
pair stored in the file RealKeyPair.snk. The ¨CR option specifies to Sn.exe
to re-sign a previously signed or delay-signed assembly.

sn ¨CR MyApp.resources.dll RealKeyPair.snk

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/htm
l/cpconcreatingsatelliteassemblies.asp

Best regards,

Peter Huang
Microsoft Online Partner Support