>the conversation passed to one of the free UIN
In a sense, managers are also using ICQ will be sitting and their contacts will be your bot? Not very convenient, much better would be a web interface or simple GUI application for them to write
And so, libraries for working with ICQ Protocol for any language in bulk. There are for PHP, Perl, Python, etc.
Do explain what you have difficulty? You at least started to do what? A particular problem was found or no idea how to do this?