类似这样的:

library(openxlsx)
library(dplyr)

# Get existing data and append new data
dat = readWorkbook("Reporting.xlsx", sheet="August")
dat = bind_rows(dat, new_data_frame)

# Write updated data frame to existing worksheet
wb = loadWorkbook("Reporting.xlsx")
writeData(wb, "August", dat)

# Save file (with new name for testing purposes)
saveWorkbook(wb, "Reporting_test.xlsx")

# To overwrite the pre-existing data file, you can do the following (commented out for safety)
#saveWorkbook(wb, "Reporting.xlsx", overwrite=TRUE)