Integration between CRM 2011 and External DB

Hi all,

In my project I am integrating with CRM 2011(On premises) with oneexternal database. I have one ID field in CRM form which represent the external db, also depend on that particular ID field some others field will populate data from that external db.

For database connection, i have created a connector(using .net) which will return data from external db.
eg: Account nameXYZ have the reference number like 123. now if I call a method to fetch account name from external db by reference number[like:method1(123) ] it will return company name [like: XYZ].

Now I want to run this method for page_load event of CRM account form, thus when a particular account record will open, the system will call themethod from dll to fetch the details related to that particular ID(Accout record which I just opened).

I have the DLL ready, but my concern is that how will I force CRM to call the methods of that DLL in the form_load event of account form?