How do I insert soft hyphens?

[kai]

It seems neither ctrl--, nor cmd-- give me soft hyphens, though the latter gives me a hard hyphen.

[s.habe]

I have used the really ugly way around this problem:

1) I activate hyphenation in one block
2) I take a copy of automatic soft hyphenation sign and copy-paste it where I need.

Sure this is not comfortable way to do it. Thus, I'd really appreciate someone putting the key to shortcut for soft hyphen here. Or if someone explained how to create one.