I understand that the question was not very clear, so I have rewritten it.

Imagine the situation.

1. Somebody makes a phone call on the number 01843668832.
2. The phone call goes through external company witch capture information such as caller telephone number, call lenght etc.
3. I pull stats from external company about this phone call using SOAP API.
4. Now I got this information and I am pushing it to SalesForce.
5. Salesforce receive this information and shows the pop up with received information to the agent.

My question is how do I achieve step 4 & 5?

Another thing is that I will need to do this for multiple Salesforce accounts. For example I will have 3 different accounts on SF.

Account A, Account B, Account C.

I will have have three different phone numbers:

number 123 - Belonging to Account A
number 456 - Belonging to Account B
number 789 - Belonging to Account C

I will have access to the phone call stats for all of these numbers.

I will get permission to access and change Account A, B & C Salesforce data using oAuth2 authentication.

When phone call happen to number 123 I want the pop up to show only for Account A.
When phone call happen to number 456 I want the pop up to show for Account B.
And so on.

Do I have to create Visual Force page or can that be places in standard Sales Force page (standard layout)?

Can this be achieved using Salesforce Open CTI ?