Assuming you have been through the motion to open Excel via VBA.
This is a mothode I use to add two dates to specific cells every time I run and import data from Excel.
It may work for you.
With objXL
.Visible = True ' or False if you don't want Excel open
Set objWkb = .Workbooks.Open(conWKB_NAME)
'On Error Resume Next
Set objSht = objWkb.Worksheets("NetOfficeData")
' objWkb.Windows("NetOfficeData").Visible = True
objWkb.Worksheets("NetOfficeData").Activate
.Cells(1, 3).Value = Format(Forms![frmQueryDates]![BeginningDate], "mmm dd, yyyy") & " 08:00:00"
.Cells(2, 3).Value = Format(Forms![frmQueryDates]![EndingDate] + 1, "mmm dd, yyyy") & " 07:59:59"
Hennie