I'm trying to use a AutoHotkey macro to send an EM_REPLACESEL message (194 or 0xC2) to a Scintilla control to insert text in an application that I am using. Although it works with standard edit controls, in any Scintilla control I try using it on, it only sends the first character in the string to be sent (it inserts two ASCII characters if the first character in the sent string is Unicode). I've tried using its counterpart specifically designed for Scintilla (SCI_REPLACESEL, 2170), but that always causes an access violation and crashes the application. According to the Scintilla documentation, EM_REPLACESEL should still be supported. Are these expected behaviors?