Hi Gruber,

Do you want to use a CDMA version of Milestone in Poland? Where did you buy it?

No one will have this code for you, it is unique for every phone and if 000000 does not work you will have to talk to the carrier that the phone was bought from.

 

If your Milestone is SIM Locked you will need an unlock code from your carrier.

 

The SPC code is for CDMA phones (No SIM). This Unlocks it for you from most restrictions a carrier sets (such as locking it to their company, or disabling connectivity settings).
However, the Milestone uses GSM (With a SIM Card). This would require a SIM Subsidy Unlock code. Once you obtain one and enter it into your Milestone, this lets you use your Milestone with any carrier's SIM card. Once you unlock the phone, it will always be unlocked (it doesn't lock to whatever the next SIM is you put in). In most cases, the carrier who sold you the phone will provide you with one after meeting certain conditions. If not, there are many third party companies who can assist you.

If you're looking to do something like remove locked applications, or change firmware that your carrier installed; then what you're looking to do is root your Milestone. There are a few threads around this forum for instructions on how to do so.