Launch shell process under different identity

[Trips]

Hello Folks

I have been having headache solving this and now I need your help

I have developed an windows application which access network resources under differnt authenticated identity and not the client who is running the application

The application runs on client machine and it has to access a network folder by impersonationg a specific user and downloads the file on client computer

Now when user clicks on download/copy button I change the Application identity to a user who has access to that network share and try downloading it by launchihng a shell process
Here is the problem, When I change the application identity and try launching the shell copy command nothing happens the shell opens up for a second and closes. If I remove the impersonation then I am able to launch the shell and file gets copied
If I use the impersonation code the shell launches and nothing happens and the shell command is just to execute a bat file
c:\abc.bat

Is there anything I have to do to launch a shell when the windows application is runing under different identity

Any help is greatly appreciated

Thank
Aja