Hi Abdulla,
You can use copy and move DOS commands in the custom commands. To use the custom commands in your deployment utility, you can select the installer options tab, select custom command, and then click on "add" to add a new command. Then type your command in the command and Arguments window.
In reference to the error, can you post a screenshot of the error and or describe the error in more detail? You can as well try creating a batch (.bat) file with the DOS command and see if that solves the problem.
I hope it helps,
Rajiv Garg