R Forecasting in Excel using the BERT console

Does anyone know how I can use the "forecast" function from R in Excel through the BERT console? I tried writing the following function:

Forecast.sea <- function(x,h){
  ts.data <- predict(x,h)
  return(ts.data)

}

but i got the error below.

Error in ets(object, lambda = lambda, biasadj = biasadj, allow.multiplicative.trend = allow.multiplicative.trend, : y should be a univariate time series Thanks, (-Alex)