1、直接更改显示图标中的属性
看看这个范例对你可能有帮助
 Dynamic Text by Ramon Morales
2、用外部控件或其他方法
有个DispText.u32不知是否满足你要求？
 Disptext.u32及其例子

id := DisplayText(WindowHandle, text, left, top, font, size, style, color)

Displays a line of text in the presentation window at the specified position.
font    the name of the font ("" for default)
size    point size (0 for default)
style    0 plain, 1 bold, 2 italic, 4 underline, 8 strikeout
    (values may be added to combine styles)
color    0 black, or (red*256*256 + green*256 + blue)
    where red, green, and blue are values from
    0 to 255

Returns non-zero object ID or 0 if error occurred.