@EXECSTR has trouble with Unicode when n < 0

C:\>ver /r

TCC  30.00.22 x64   Windows 10 [Version 10.0.19044.3324]
TCC Build 22   Windows 10 Build 19044
Registered to COE-LN00074120

C:\>type test1.btm
@echo off
for /l %i in ( -10, 1, 10 ) echo %i - %@execstr[%i,babble.exe]

C:\>option //unicodeoutput=yes

C:\>test1.btm
-10 - ABCDE αβγδε АБВГД אבגדה
-9 - ABCDE αβγδε АБВГД אבגדה
-8 - ABCDE αβγδε АБВГД אבגדה
-7 - ABCDEFGHIJKLMNOPQRSTUVWXYZ...