\documentclass{book}
\usepackage{pgffor}
\usepackage{alphalph}
\usepackage{xepersian}
\settextfont{Yas}

\makeatletter
\newcommand{\@AlphAlph}{}% Check that \@AlphAlph is undefined.
\let\@AlphAlph=\AlphAlph
\makeatother

\newcommand\InsertBlankPages[1]{% \InsertBlankPages{n} => insert n blank pages
	\foreach \blank in {1,...,#1} {
		\newpage
		\thispagestyle{plain}
		\mbox{}
	}%
}


\begin{document}
\pagenumbering{AlphAlph}	
\pagestyle{plain}
%\InsertBlankPages{28}
%\InsertBlankPages{29}
\InsertBlankPages{32}	
\end{document}