You should not add specific references to the local system in the user initialization file. You want the instructions in a user initialization file to be valid regardless of which system the user logs into.
To make a user's home directory available anywhere on the network, always refer to the home directory with the variable $HOME. For example, use $HOME/bin instead of /export/home/username/bin. The $HOME variable works when the user logs in to another system and the home directories are automounted.
To access files on a local disk, use global path names, such as /net/system-name/directory-name. Any directory referenced by /net/system-name can be mounted automatically on any system on which the user logs in, assuming the system is running AutoFS.