library(RDCOMClient)
e = COMCreate("Excel.Application")
book = e[["Workbooks"]]$Add()
sheet = book[["ActiveSheet"]]
e[["Visible"]] = 1


r = sheet$Range("A13:E15")
r[["Value"]] = "a"

# Doesn't work
sheet$Range("A13:E15")[["Value"]] = "a"