that dialog has these arguments

xlDialogOpen file_text, update_links, read_only, format, prot_pwd, write_res_pwd, ignore_rorec, file_origin, custom_delimit, add_logical, editable, file_access, notify_logical, converter

if you want to change the title you will need to use the getopenfilename

Dim vntFilename As Variant

vntFilename = Application.GetOpenFilename("Excel files (*.xl*),*.xl*", , "My Dialog Title")
If vntFilename = False Then
    ' nothing selected
Else
    MsgBox "User selected " & vntFilename
End If