求教：语句 hostname | set /p aaa= 如何才能正确执行
小弟近日遇到个问题 ，无法理解 ，特来求教 ！
批处理中需要执行以下命令：
set myname=DN001 DN002 DN003 DN006 DN007 DN008 DN011 DN012 DN013 DN017 DN018 DN020 DN021 DN022 DN025 DN026 DN027 DN030 DN032 DN033 DN034 DN036 DN039 DN040 DN041 DN043 DN045 DN048 DN049 DN050 DN053 DN055 DN057 DN058 DN059 DN061 DN063 DN066 DN067 DN068 DN069 DN070 DN074 DN075 DN076 DN079 DN081 DN083 DN084 DN085 DN087 DN089 DN091 DN093 DN095 DN097 DN100 DN102 DN104 DN106 DN107 DN110 DN113
hostname | set /p aaa=
for %%i in (%myname%) do if %aaa%==%%i start abc.exe
其中语句：hostname | set /p aaa= 让变量aaa获得 hostname的值 ，语句在命令行中没有提示出错，可aaa就是无法获得值，因此不能正确执行，是哪里不对？
虽然最后用 语句 if %computername%==%%i start JKNBMS\JKNBMS.exe 代替成功，
但语句 hostname | set /p aaa= 依旧无法解决，还请大神出手