Take a few minutes to go over the dimension variables (dimvars) in Appendix E. You can set each of these at the command line simply by typing the dimvar and a value.
Then take a look at the command line approach to dimension styles. It looks like this:
Command: -dimstyle
Current dimension style: arch [AutoCAD tells you which style is current]
Enter a dimension style option
[Save/Restore/STatus/Variables/Apply/?] <Restore>: [hit enter to make a different style current]
Enter a dimension style name , [?] or <select dimension>: [type the name of the dimension style you wish to make current]
Use the Save option to create a new style based on the current dimvar settings. Use the Restore option (the default) to switch from one style to another.
The STatus option will show you the current settings of the dimvars.
Using the Variables option, you can select a dimension and read the values of the dimvars used to create that dimension.
The Apply option will change user -selected dimensions so they use the current dimvars.
This should make you appreciate the Ddim command and the Dimension Style Manager!