BCGControlBar Pro for MFC
BOOL CBCGPGlobalUtils::EnableEditCtrlAutoComplete ( HWND  hwndEdit,
BOOL  bDirsOnly,
LPCTSTR  lpszCurrentDirectory = NULL,
BOOL  bThemedDropDownList = BCGP_DEFAULT,
LPCTSTR  lpszFileFilter = NULL 
)

Enables or disables the shell autocomplete list for the specified edit control.

Parameters
hwndEditThe edit control.
bDirsOnlySpecifies whether the drop-down list should contain the directories only.
lpszCurrentDirectoryThe pointer to the current directory.
bThemedDropDownListSpecifies whether the drop-down list should be themed.
lpszFileFilterThe optional file filter (in the same format as in the file dialog, e.g., _T("*.cpp;*.h"). Relevant only if the drop-down list is themed and the "bDirsOnly" parameter is FALSE.
Returns
True if it succeeds, false if it fails.