GuiControl, Sub-command, ControlID [, Param3]
GuiControl, (blank):
Tab/DropDownList/ComboBox/ListBox: Param3 should contain a pipe-delimited list of entries to be appended at the end of the control's list. To replace (overwrite) the list instead, include a pipe as the first character (e.g. |Red|Green|Blue). To make the control empty, specify only a pipe character (|). To have one of the entries pre-selected, include two pipes after it (e.g. Red|Green||Blue). The separator between fields may be changed to something other than pipe. For example, Gui +Delimiter`n would change it to linefeed and Gui +DelimiterTab would change it to tab (`t).