I have a sheet that looks like this: sample data
What I want to do is fill values in empty cells using data from some other excel file, but without overwriting the other data (and it's formatting). After some search I found that the command "setStyleAction" in XLConnect allows to do it (though I could not check if it works), but I need to use the "xlsx" package instead, due to some other limitation of XLConnect. Is there equivalent function in "xlsx" package? It has been mentioned in some other answers that there is actually one, but nobody mentioned what function, also I myself couldn't figure it out. Can somebody please tell me any such function, or some other way altogether to add data to specific cells without changing data in other cells of same sheet?