Sub Macro1()
'
' Macro1 Macro
'

'
    Range("B1:Q1").Select
    With Selection
        .HorizontalAlignment = xlCenter
        .VerticalAlignment = xlBottom
        .WrapText = False
        .Orientation = 0
        .AddIndent = False
        .IndentLevel = 0
        .ShrinkToFit = False
        .ReadingOrder = xlContext
        .MergeCells = False
    End With
    Selection.Merge
End Sub 
##</code><code>##

use Win32::OLE qw(in with CP_UTF8);
Win32::OLE->Option(CP => CP_UTF8);
use Win32::OLE::Const 'Microsoft Excel';
use Win32::OLE::Variant;
$Win32::OLE::Warn = 3;                                
my $Excel = Win32::OLE->GetActiveObject('Excel.Application') || Win32::OLE->new('Excel.Application', 'Quit');  # get already active Excel
$Excel->{'Visible'} = 1;
my $Book = $Excel->Workbooks->Open('foo.xlsx'); 
my $Sheet = $Book->Worksheets(1); 
$Sheet->Range("B1:Q1")->Merge();
$Sheet->Range("B1:Q1")->{HorizontalAlignment} = 'xlCenter';

##</code><code>##

Win32::OLE operating in debugging mode: _Unique => 1
OLE exception from "Microsoft Excel":

Unable to set the HorizontalAlignment property of the Range class

Win32::OLE(0.1709) error 0x80020009: "Exception occurred"
    in PROPERTYPUT "HorizontalAlignment" at C:\Users\boss\Dropbox C:\tmp\merge-center.pl line 11.