Ok, I don’t know exactly which registry key you mean (you specified two).
Depending if you want the double quotes or not, try either…
concatenation “,” of ("%22" & name of it & “%22=%22” & it as string & “%22”) of values of key “HKEY_LOCAL_MACHINE\SOFTWARE\Policies\SNMP\Parameters\PermittedManagers” of registry
or
concatenation “,” of (name of it & “=” & it as string) of values of key “HKEY_LOCAL_MACHINE\SOFTWARE\Policies\SNMP\Parameters\PermittedManagers” of registry