You may be encountering WOW redirection so your command being excuted as 32 bit will cause the registry to be updated under “HKLM\Wow6432Node\SOFTWARE\Candle\K51\Ver622\Primary\Environment”.
You could try disabing redirection using the action uses wow64 redirection actionscript, or a more direct approach could be the regset and regset64 actionscript commands, eg
if {x64 of operating system}
regset64 "[HKEY_LOCAL_MACHINE\SOFTWARE\Candle\K51\Ver622\Primary\Environment]" "CT_CMSLIST"="IP.PIPE:#172.30.101.24;IP.PIPE:#172.30.101.20"
else
regset "[HKEY_LOCAL_MACHINE\SOFTWARE\Candle\K51\Ver622\Primary\Environment]" "CT_CMSLIST"="IP.PIPE:#172.30.101.24;IP.PIPE:#172.30.101.20"
endif