Karen, I am dreadfully sorry that you do not have a longer list to choose from.
I was dreadfully sorry you had to miss that supper.
How dreadfully sorry I am that we can't continue this charming conversation.
We can sympathize and feel dreadfully sorry, but we're not inside his skin.
I'm dreadfully sorry, I really don't know, that just popped out.
I'm dreadfully sorry that you had to be called in.
I'm dreadfully sorry you had to walk this long distance, out here in the wilds.
Peter, I'm dreadfully sorry it took me so long to get back to you.
One would be dreadfully sorry, of course, and blame oneself.
Dreadfully sorry, but I looked all over for you.