The MaxRM Remote Command Line presumably operates in the context of the MaxRM agent service’s logon, which by default is SYSTEM. It’s unlikely (or perhaps not possible) to lock out the SYSTEM account.
If you can open the MaxRM Remote Command Line on a domain controller (or maybe another domain-joined machine), you can check the status of an account and, if necessary, unlock it as follows:
net user <UserName> /DOMAIN | FIND /I “Account Active”
net user <UserName> /active:yes