The DIF_EDITEXPAND flag "expands" environment variables after completion of dialog
execution (for example, %TEMP% will be expanded to C:\TEMP)
The DIF_EDITEXPAND flag is applicable to the following dialog items:
| Control | Description |
|---|---|
| DI_COMBOBOX | Combo box. |
| DI_EDIT | Edit box. |
Environment variables "expansion" is done by using the ExpandEnvironmentStrings function, so if some %VariableName% value doesn't exist in the environment, it will remain untouched.