Path being filled with the subdir only

[Heime]

I want to have lana-path to be "~/Opstk/src/Nadin/nadin-1.0", but I am only 
getting
"/typex/lana".  

    (let* ( (lana-subdir "/typex/lana")

            ;; Determine the base path: argument, env var, or default
            (base-path
                (or nadin-bspt
                    (getenv "NADIN_PATH")
                    (and (file-directory-p (substitute-in-file-name 
"$HOME/Opstk/src/Nadin/nadin-1.0"))
                         (substitute-in-file-name 
"$HOME/Opstk/src/Nadin/nadin-1.0"))
                    (expand-file-name "~/Opstk/src/Nadin/nadin-1.0")))

            ;; Construct the full path
            (lana-path (expand-file-name lana-subdir base-path)))