Источник
http://forum.foxclub.ru/read.php?29,239688,239688

Автор - В.Клепинин

#define CF_BITMAP 2
#define CF_PALETTE 9
#define OBJ_BITMAP 7
#define PICTYPE_BITMAP 1
#define IID_IDispatch Chr(0x00)+Chr(0x04)+Chr(0x02)+Chr(0x00)+ ;
Replicate(Chr(0x00), 4)+Chr(0xC0)+Replicate(Chr(0x00), 6)+Chr(0x46)
Declare Long OpenClipboard in Win32API Long hWnd
Declare Long CloseClipboard in Win32API
Declare Long GetClipboardData in Win32API Long
Declare Long DeleteObject in Win32API Long
Declare Long GetObjectType in Win32API Long
Declare Long OleCreatePictureIndirect In oleaut32 String @, String @, Long, Object @
hBmp = 0
IF OpenClipboard(0) != 0
hBmp = GetClipboardData(CF_BITMAP)
hPal = GetClipboardData(CF_PALETTE)
CloseClipboard()
ENDIF
If hBmp = 0 Or GetObjectType(hBmp) <> OBJ_BITMAP
= MESSAGEBOX("Это не BMP")
RETURN
ENDIF
lcPictDesc = BINTOC(16, "4RS") + BINTOC(PICTYPE_BITMAP, "4RS") + BINTOC
(hBmp, "4RS") + BINTOC(hPal, "4RS")
iid = IID_IDispatch
IPic = 0
OleCreatePictureIndirect(@lcPictDesc, @iid, 1, @IPic)
= SAVEPICTURE(IPic, "d:/pict.bmp")
DeleteObject(hBmp)
= MESSAGEBOX("ok")

И вот еще, ссылка

http://www.tek-tips.com/faqs.cfm?fid=4824

Screen Capture/JPG/BMP/Wallpaper, тут еще dll надо скачать,

http://www.vfug.org/files/pct_dll.zip