[hp1nt0]

Код:

setlocal enableextensions enabledelayedexpansion
for %%f in ( "%SequenceFolder%\*.png" ) do (
set/a FrameNumber+=1& set "FrameDigits=00!FrameNumber!"
.\bin\magick -size 100x14 xc:none -gravity center ^
          -stroke black -strokewidth 2 -annotate 0 "!FrameDigits:~-3! of %FileNumbA%" ^
          -background none -shadow 100x3+0+0 +repage ^
          -stroke none -fill white     -annotate 0 "!FrameDigits:~-3! of %FileNumbA%" ^
          %%f  +swap -gravity southwest -geometry +0-3 ^
          -composite  .\img\1seq\%%~nxf
set "!FrameDigits:~-3!=FrameNumber"
)

Так работает.