Hi Nurak,
That should be possible but you have to add an Unique Indentifier in your CSV File for example MAC Address or Serial Number or UUID....
To import a computers in the DS Console try the following:
Take a look on your Express Share (Share on your Deployment Sever) under the Samples Folder there is a File called ImportComputers55.txt this file is an example for an Import file.
You can use this file when you rightclick in the Deployment Server Console under Computers -> New Computers and then click on Import... and select your CSV File or try the file in the sample folder.
Hope this helps
Network23