Check this out:
the prefix service parameters work fine for North American Dial Plan, but I am not sure if they do with your dialplan, it's worth trying as that is the easiest solution.
I am trying to avoid using the service parameters to accomplish this. This site uses a different outbound access code than the rest of our IPT sites. Can this be done this a translation pattern?
Chris - I have a translation pattern "089540924XX" which will translate to the internal ext 73790XX on the "prefix digits" (outgoing calls) I can add a 000 (one zero to grab an outside line and the 00 for an international call), however for local calls it needs to be 00. How can I accomplish this? Ideas?
What CUCM version?
ALWAYS mention what call control agent and version you're using when posting.
There is no way to do what you want in CUCM, translation patterns cannot distinguish between local or international calls.
You probably can do this directly in a H323 GW if the calls are correctly tagged as international.
With MGCP only using the parameters.
if this helps, please rate
What CLI is displayed on the different type of calls? is it just the case of wanting to have the local PSTN code to be added which is unique per country?. If I`m reading your post correctly you have a global cluster in different counties with different PSTN access codes. In CUCM 7.0 you have the service parameter the previous users have mentioned as a Cluster wide option but now you also have it on each unique GW but only on CUCM7.X so it may not help however if you only need add the different countries prefix then you can add it via a TP in CUCM even when using MGCP
1. Create a Partition for each GW concerned PT-GERMANY
2. Create a CSS for each GW as well
3. Assign the PT-GERMANY to the new CSS
4. GW, Go to your inbound calls, and change the css to the new GW CSS
5. Create a translation pattern for all your incoming DID calls...Eg if your Full DDI is 02079011226, then if you are using 4 digit, your Xlation pattern will be something like 12XX or 1XXX,
6. Add the PT-GERMNAY to this TP
7. Ensure that the CSS for the new TP can see your internal Germany users
On the Calling party xformation mask, you can either use prefix outgoing digits  or use calling party transformation mask 0XXX....(the number of digits you want)
The prefix outgoing digit is easier, so use that..
In Germany you need to confirm the number of digits as they are flexible in the digits they send
you can use the service parameters. For subscriber 0, national 00 and international 000.
You find the service parameters in the call manager section under advanced.
Ps: I'm from Germany and used this.
If you convert the gateway to H323 then you can accomplish this easily. All you need is an calling translation pattern associated with the serial interface as below:
voice translation-rule 201
rule 1 // /00/ plan national national
rule 2 // /000/ plan unknown unknown
rule 3 // /00/ type national national
rule 4 // /000/ type international international
voice translation-profile INCOMING_CLI
translate calling 201
translation-profile incoming INCOMING_CLI
input gain 3
output attenuation -3
MGCP gateways are, to be honest, a pain in the neck. I only every use them if connecting to another telephone system via QSIG.