How about

[VBA]
Private Sub CommandButton1_Click()
Dim myVocab As Object
Dim myfullPath As String
myfullPath = ActivePresentation.Path & "\Task.xls" 'Excel file

Set myVocab = GetObject(myfullPath)
With myVocab
.Activate
.Windows(1).Visible = True

.Sheets("Grid").Range("A2") = "14" 'Text to transfer
End With

myVocab.Close
Set myVocab = Nothing

End Sub
[/VBA]