>You may set date column NumberFormat to 'dd/mm/yyyy'
>
>Where should I use NumberFormat to 'dd/mm/yyyy' in my procedure?

set safety off
use ?
als1=alias()
if !empty(als1)
local lnI, lnDCol
local array laCols[1,2], laFields[1]
=afields(laFields)
lnDCol = 0
for lnI = 1 to alen(laFields,1)
     do case
        case laFields[m.lnI,2] = 'D' && date
            lnDCol = m.lnDCol + 1
            dimension laCols[m.lnDCol,2]
            laCols[m.lnDCol,1] = m.lnI
            laCols[m.lnDCol,2] = 'mm/dd/yyyy'
        case laFields[m.lnI,2] = 'T' && datetime
             lnDCol = m.lnDCol + 1
            dimension laCols[m.lnDCol,2]
            laCols[m.lnDCol,1] = m.lnI
            laCols[m.lnDCol,2] = 'mm/dd/yyyy hh:mm:ss'
        endcase
next
	gcdelimname =alias() + '.xls'
	gcdelimfile = putfile('excel_file:', gcdelimname, 'xls')
	if !empty(gcdelimfile)
		copy to (gcdelimfile) type xl5 && Create Excel
	endif

	res=messagebox("Do you want to Open " + gcDelimName,4+32+512,"Dbf2Xls")
	if res=6
		loexcel = createobject("Excel.Application")
		loworkbook = loexcel.workbooks.open(gcdelimfile)
		losheet = loworkbook.sheets(1) 
                  for lnI = 1 to alen(laDCols,1)
                      loSheet.Columns(laDCols[m.lnI,1]).NumberFormat = laDCols[m.lnI,2]
                  next
              	losheet.columns().autofit() 
		loexcel.visible = .t. && display Excel
	endif
endif

Something like this, from the top of my head and not tested.