After placing the cursor at the desired position using the SelStart property,
you should use the EM_SCROLLCARET message to scroll the caret into view,
as shown in the piece of code below.
(To set the SelStart property to a x/y coordinate, also read this tip:
Access the current row/column of a TMemo.)
// scroll caret into view,
// the wParam, lParam parameters are ignored
SendMessage(Memo1.handle, EM_SCROLLCARET,0,0);