An EA to block account under certain conditions

To minimize risk of our company traders' accounts, we need an EA able to block an MT4 account if it reaches customizable daily stoploss limit or account stoploss limit. The goal is to prevent traders from opening new positions if they reach the limits. This can be done by an EA with imported DLL that can change account password once limit is reached. Feel free to suggest another way how to prevent traders from opening new positions if they reach one of the stoploss limits.