Use the following in a btach file for installing the prerequisites for Exchange 2007:
CAS SERVER & HUB TRANSPORT
ServerManagerCmd -i PowerShell
ServerManagerCmd -i RSAT-ADDS
ServerManagerCmd -i Web-Server
ServerManagerCmd -i Web-ISAPI-Ext
ServerManagerCmd -i Web-Metabase
ServerManagerCmd -i Web-Lgcy-Mgmt-Console
ServerManagerCmd -i Web-Basic-Auth
ServerManagerCmd -i Web-Digest-Auth
ServerManagerCmd -i Web-Windows-Auth
ServerManagerCmd -i Web-Dyn-Compression
ServerManagerCmd -i RPC-over-HTTP-proxy
MAILBOX CCR
ServerManagerCmd -i RSAT-ADDS
ServerManagerCmd -i PowerShell
ServerManagerCmd -i Web-Server
ServerManagerCmd -i Web-ISAPI-Ext
ServerManagerCmd -i Web-Metabase
ServerManagerCmd -i Web-Lgcy-Mgmt-Console
ServerManagerCmd -i Web-Basic-Auth
ServerManagerCmd -i Web-Windows-AuthServerManagerCmd -i Failover-Clustering