Loop exporting to excel file- writeWorksheetToFile

I need to read multiple dta files and exporting the content of a variable
called "name". My idea is to aggregate to the right each "name" from each
dta file. I made a simple loop and I know It works reading the dta files.
However, It can't say the same exporting the data.

Here is what I wrote:

options(java.parameters = "-Xmx4096m")

file = list.files(pattern="\\.dta$")
myFiles <- list.files(pattern = "\\.dta$")

for(i in myFiles){
    for (j in 1:length(file)) {
  myDf = read_dta(i) 

  writeWorksheetToFile("datos.xlsx",data=plop, sheet="variables",startRow=1, startCol=j)
Every time I run the code I received a message with "Error: POIXMLException
(Java): java.lang.reflect.InvocationTargetException".
And when I opened the excel file, It only contained in the first column
infomatio (plop) of the first dta file.
I have no idea what else to do. The error seems related to the intent to
export the data to excel than reading the files.
Thanks for your time and interest.
I've made some test I found out that the package XLConnect isn't reliable when you try to make some loops.
So, I just decided to append every database and after the last file is appended, I've exported using the XLConnect package.
If you ask me how do I know the package XLConnect fails, It is because I can perform partially the code. Using around the 20th file It stops and reports the "Error: POIXMLException
(Java): java.lang.reflect.InvocationTargetException" message.