\DeclareRobustCommand + argument of argument

Is impossible make somthing like this?

\documentclass[a4paper]{memoir}

\usepackage{microtype}

\DeclareRobustCommand{\spacedlowsmallcaps}[1]{\textls[80]{\scshape\MakeTextLowercase{#1}}}%

\microtypesetup{expansion=false}%

\DeclareRobustCommand{\spacedallcaps}[1]{\textls[160]{\MakeTextUppercase{#1}}}%

\DeclareRobustCommand{\spacedallcapsB}{\spacedallcaps{\Large}}%

\begin{document}
{\spacedallcapsB Hallo}
\end{document}

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I need to add \usepackage{textcase} to run your MWE –  David Carlisle Aug 11 '12 at 14:11
You are just uppercaseing the token \Large which cleally doesn't do anything. What result do you intend? –  David Carlisle Aug 11 '12 at 14:13
Massive. ........... –  Nicholas Hamilton Aug 24 '13 at 16:44

This is a bit of a wild guess as to the intended result.

\documentclass[a4paper]{memoir}
\usepackage{textcase}
\usepackage{microtype}

\DeclareRobustCommand{\spacedlowsmallcaps}[1]{\textls[80]{\scshape\MakeTextLowercase{#1}}}%

\microtypesetup{expansion=false}%

\DeclareRobustCommand{\spacedallcaps}[1]{\textls[160]{\MakeTextUppercase{#1}}}%

\DeclareRobustCommand\spacedallcapsB{\afterassignment\xspacedallcapsB\toks0\bgroup}
\def\xspacedallcapsB{\Large\spacedallcaps{\the\toks0}\egroup}

\begin{document}
{\spacedallcapsB Hallo}
\end{document}

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