Curious case of the transaction AL11. Please Help.

Recentlycreated a programthat needed togeneratea txt filein theSAP application serverthat at the endof each line oftxt fileshouldbe createdblanksto complete500characters.
The file is createdcorrectlythrough thefunction moduleGUI_DOWNLOAD(with import parameter"TRUNC_TRAILING_BLANKS_EOL" with the value"space").
When I openthe filethroughtransactionAL11,each line of thefile isin the blankscorrectly,until they turn500characters.
But when,throughAL11,I exportthe file(TXT)inanylocal folder,the spacesat the endof each linedisappear.

Thisfile shouldbe500characters per line,always.
Thisfile shouldsent toa banking system(notSAP) that validatesmy filethisstrange way.(500characters per line).

My question.
How toexport this fileso that it isexactly as it appearsinAL11(with 500characters per line)?

Thanksto all andsorry forspelling errors.