Thanks!
Now it works!

I tried this:
DoMethod(sci, SCI_Command, SCI_INSERTTEXT, "Hallo", 0)

But now reading the docs, I found out that, the second argument is the text to add;)

I wanted to write a small "IDE" for ecx, since Scribble can fold only in c-sources, and building a project for ecx only works with a faked makefile, also the function-lister only works for c sources...

But after a short reading in the docs, it seems that I have to add all the neat stuff Scribble already has like syntax-highlighting, folding, a function-lister already exists;), hotkey binding etc all by myself;(

I thought/hoped they could be enabled via an attribute in the mcc;)