We have no designated 200 STATION

Usually the operator's extension is the programming extension. Ext 200 is the default operator's extension.

You dial 200 and it rings a phone line not an individual phone? Do you know what your extension numbers are? (Some people never use them and do not know) If you do know some or all of your extensions, what is the lowest extension number?

For me to get you specific information, it would help to know which Toshiba phone system you have. (Not a phone) The systems all program differently. Did you obtain the manual recently and are you sure it is the correct manual for your specific Toshiba system? Again, the system is not a phone and your phone's model number does not narrow it down. All the Toshiba phone systems have a name and number on the front cover. Example: "Toshiba Strata DK 280"