Create playlist once in Windows and use in Android Is there a way to do this?
I have .mp3 files in a folder on my Windows PC and the same folder on android.
It is possible but you must modify the playlist file by changing the path to the files because they (the files) are not located in the same folder. In Windows, the path will look like C:\Users\A_User\Your_Folder\music.mp3 will on your device it will be like /sdcard/your_folder/music.mp3 (find the path to your files on your device using your file manager).

After creating the playlist, open it with Notepad. If your playlist has m3u extension (it might differ, see note below), it will look like this:

#EXTM3U
#EXTINF:279,Papa Wemba - Maria
file:///C:/Users/Reddy/Desktop/New%20folder%20(5)/Music/Maria.mp3
#EXTINF:217,Papa Wemba - Okoningana
file:///C:/Users/Reddy/Desktop/New%20folder%20(5)/Music/Okoningana.mp3


Change the path by removing C:/Users/Reddy/Desktop/New%20folder%20(5)/Music/ in the example above with sdcard/your_folder/. Thus, the playlist will change to:

#EXTM3U
#EXTINF:279,Papa Wemba - Maria
file:///sdcard/your_folder/Music/Maria.mp3
#EXTINF:217,Papa Wemba - Okoningana
file:///sdcard/your_folder/Okoningana.mp3


Transfer the file to your device, and you will be able to play it.

Note: The playlist in the example was created using VLC media player in a Windows machine and playing it using VLC for Android. Yours may differ a bit depending on the media player used or file extension ( xspf, m3u8, even m3u, etc). However, the principle is the same: change the path.

Disclaimer: I am only a VLC user, not its developer(s) or related to him/her/them.