Writes
            application data to the AppData section of the acad*.cfg file
         
         
         Arguments
         
- cfgname
- 
               
                  A string that specifies
                     the section and parameter to set with the value of cfgval.
                     The cfgname argument must be a string
                     of the following form:
                   AppData/application_name/section_name/.../param_name The string can be up
                     to 496 characters long.
                   
 
- cfgval
- 
               
                  A string. The string
                     can be up to 512 characters in length. Larger strings are accepted
                     by setcfg, but cannot be
                     returned by getcfg.
                   
 
Return Values
         
         If successful, setcfg returns cfgval.
            If cfgname is not valid, setcfg returns nil.
         
         Examples
         
         The following code sets
            the WallThk parameter in the AppData/ArchStuff section to 8, and
            returns the string “8”: 
         
         Command: (setcfg
               "AppData/ArchStuff/WallThk" "8")
         "8"