Moving the Caret with OS X Text Substitution
I don't think it's possible. You might add a snippet like this in TextExpander though:

Thank you %|.


Or use DefaultKeyBinding.dict:

{
    "\UF704" = { // F1
        "t" = {
            "h" = {
                "x" = (insertText:, "Thank you .", moveBackward:);
            };
        };
    };
}