Versions 2003 and 2004
Starting witht the 2003 version, you can compile your structure file directly from the 4th Dimension application. This compilation process doesn't create a compiled structure for you, but rather creates the compiled code within the interpreted structure. However, this compiled code can be removed from the structure from the Compiler Window:
In 2003, expand the Options area and click on the "Clear" button.
In 2004, simply click on the "Clear compiled code" button at the top of the window.