If formatting is a concern, you could use TEXT() like this with the deliminaters explicity included between the TEXT()'s

=TEXT(A1,"#,##0.000_);(#,##0.000);0.000")&" "&TEXT(A2,"#,##0.000_);(#,##0.000);0.000")&" "&TEXT(A3,"#,##0.000_);(#,##0.000);0.000")

or as part of the format string

=TEXT(A1,"#,##0.000_); (#,##0.000); 0.000")&TEXT(B1," #,##0.000_);( #,##0.000); 0.000")&TEXT(C1," #,##0.000_); ( #,##0.000); 0.000")
Paul