Exporting Model Space or Securing Layers

Is there a way within Autocad to lock a layer so that only certain people have access (say using a password).

Also is there a way to export model space from one workbook to another. In that one is the standard company file and I want to build a sepearte workbook for my purposes (making specific paper spaces etc...) but I want to use their model space for the model space of my workbook. Also if possible to export would this exported model space make changes when changes were made on the original copy?

You cannot password protect a layer in AutoCAD.

I think you might want to look into xrefs re: the second part of your thread.

Thanks Remark can you guide me to where i might be able to locate information that would be more specific.

An example of what I am tyring to do:

Engineering department has a base topographical map. I want to use this map as the model space in a seperate file because they will not grant me access to add paper spaces and other layers onto their drawing. (Lets call their drawing the "Virgin" drawing) I am looking for a way to say export/translate the same model space to a seperate file so that I can make my adjustments but I also need the model space to update when they make changes to this "Virgin Drawing". Is this possible?

XREF TUTORIAL

XREF TUTORIAL 2

Thank you SLW so after reading the material presented I have a few questions:

1.) Technically the referenced file does not automatically revise with the original file you have to use "Reload" correct? But autocad provides you with a notification.

2.) I tried doing it in one file and the XREF drawing appeared in a light gray outline such that I am assuming it was to identify that this was an XREF drawing. Is there a way to make it normal?

3.) The XREF drawing appears as one item in that say there is a bunch of pieces making the drawing you cant select each individual piece can you?

1. Depending on XREFNOTIFY setting as to whether or not you are notified, they are updated automatically when opening the drawing.

2. Look into VISRETAIN and XDWGFADECTL.

3. Look into REFEDIT