Using Configuration Variables in Key-ins
As an alternative to using the Configuration Variables dialog ( ), you can define a Configuration Variable from the Key-in window using the key-in EXPAND SET . For example, to create a Configuration Variable MYFILE having as its value the name of the open DGN file, key in EXPAND SET MYFILE = $(_dgnfile) — note that there must be a space both before and after =.
You can also use Configuration Variables as parameters in key-ins. For example, to create a cell whose name is the name of the open DGN file (without the extension), key in $ CREATE CELL $(basename(_dgnfile)). In this example the first $ is an alias for the key-in EXPAND KEYIN . In other words, the key-in EXPAND KEYIN CREATE CELL $(basename(_dgnfile)) is equivalent. The second $ indicates what follows in parentheses is a Configuration Variable.