Dialogs are a bit trickier and I have never done this but I can assume this is the approach.
Here is how I "ASSUME" it should work
1. In the new project, create the dialog with the same name
2. Save the project.
3. Open the current project .rc file as text (this will close all dialog windows you currently have open so save all if necessary)
4. Open the old .rc file as text
5. Copy everything inbetween the BEGIN & END tags of the old dialog you want
6. Paste it into the new .rc file in the appropriate area.
7. In the old code, there is another location where the dialog is described. I dont know if this will be require or not but I think it will. If I remember correctly, this area may have size descriptions in it. Just search on the dialog name and you will find it.
Because we added the dialog first, the resource.h file should be updated.
See if this gets you wehre you need to be.
Matt