the dll is EZTW32.dll and site is http://www.dosadi.com/
and its code is :

DECLARE INTEGER TWAIN_SelectImageSource ;
IN Eztw32.DLL INTEGER hWnd
DECLARE INTEGER TWAIN_GetSourceList ;
IN Eztw32.dll
DECLARE INTEGER TWAIN_GetNextSourceName ;
IN Eztw32.dll STRING @cSourceName
DECLARE INTEGER TWAIN_OpenSource ;
IN Eztw32.DLL STRING cSourceName
DECLARE INTEGER TWAIN_AcquireNative ;
IN Eztw32.DLL INTEGER nAppWind, INTEGER nPixelTypes
DECLARE INTEGER TWAIN_WriteNativeToFilename ;
IN Eztw32.DLL INTEGER nDIB, STRING cFilename
DECLARE INTEGER TWAIN_FreeNative ;
IN Eztw32.DLL INTEGER nDIB
DECLARE INTEGER TWAIN_SetMultiTransfer ;
IN Eztw32.dll INTEGER nFlag


LOCAL lnImageHandle, lnReply


pic_name="temp\"+"_"+SUBSTR(SYS(2015), 4)+".bmp"
* Get the image
lnImageHandle = TWAIN_AcquireNative(0,0)
* Write the image to a disk file
lnReply = ;
TWAIN_WriteNativeToFilename(lnImageHandle,pic_name)

* Release the image handle
TWAIN_FreeNative(lnImageHandle)

* Check for errors
IF lnReply = 0
* image successfully written to file