求助：鼠标驱动MOUSE_INPUT_DATA结构，LastX坐标转换问题

怎么把像素坐标，比如(1024,768)，转换为LastX坐标中要求的绝对坐标，或者反过来转换。

If MOUSEEVENTF_ABSOLUTE value is specified, dx and dy contain normalized absolute coordinates between 0 and 65,535. The event procedure maps these coordinates onto the display surface. Coordinate (0,0) maps onto the upper-left corner of the display surface, and (65535,65535) maps onto the lower-right corner.    
屏幕坐标要如下转换：  
dx   =   point.x   *   65535   /   ScreenWidth;  
dy   =   point.y   *   65535   /   ScreenHeight;