Hi jan4,
Unfortunately your instruction was not clear cut.

And fortunately, I played around a bit and found out the solution.
Here is a simple tutorial on how to do it. That is create a floppy
disk with plop boot manager in it and boot off from USB drive/stick.
Assuming you have windows based PC with a floppy drive,
I am still using Windows XP, I know it is getting old.

.
Plus also a spare floppy disk.
1) Get the plop boot manager "image" for floppy disk installation.
Download this file = plpbt-5.0.12.zip from this link:
http://download.plop.at/files/bootmngr/plpbt-5.0.12.zip 2) Unzip the file, under the folder: "plpbt-5.0.12", you will see a file
called = plpbt.img. This is floppy disk image of the plop boot manager.
3) Next, download the Windows floppy image writer = rawwritewin from this link:
http://download.plop.at/files/rawwritewin.exe. This file can run in Windows.
4) Load in you spare floppy disk into floppy drive.
Run rawwritewin.exe in Windows and a window will pop up asking where to get the
image file and then write to floppy disk. So, locate the file- "plpbt.img" in your PC
and write to floppy disk.
5) Go back to the folder: "plpbt-5.0.12" and go to the "cfg" folder, you will see
the file called: plpcfgbtGUI.exe. Run this file, then a graphic user interface(GUI) version
of the plpcfgbt.exe(command prompt version) will nicely display on the your screen.
6) Locate the "plpbt bin" at your floppy disk(in A drive). And then click "open" button.
7) Next, click the button- "Hidden USB" and click the button- "Configure plpbt.bin". This
will write the settings in the file to boot up USB drive/stick automatically without
showing plop boot manager. Finally, label this floppy disk and stick into a testing
PC with floppy drive and usb stick (in the usb stick, I assume that you have
loaded an OS image)
Viola!!! The floppy will transfer the control to whatever OS that you are running in the
USB stick.
ENJOY!!!!