Equation for Data filtering

[LostNZ]

Hi I am after an equation either sumif or countif, whatever is best for the following two scenarios.

Scenario One
I have created a workbook on excel with several sheets that automatically filters names of people that have attached specific tasks they complete onto a summary sheet. The sheets tell me the numbers of tasks that they are working on at one time as this can change from week to week, month to month, etc. On this list of names or people, some I know and others I don't. The names I know I have an equation that filters their data for what I want. What I need help is to sort the data for the other names I don't know. I want to use the equation so it does this automatically and not have to manually filter and select those people. I cannot work out how to create an equation that will recognise the names of people I know and ignore them but tell me the number of tasks that I need to do something wtih because they are allocated to someone that I do not know.

So a basic idea of what it will look like and come up with would be the following for example

Sally 12
Peter 10
Jim 18
John 2

Unknown 24

The unknown people are the ones I need to do something about.

The Second part of this scenario and i am unsure if excell is able to do this would be to filter out automatically all the names of those unknown people onto another sheet within the workbook then I know exactly who they are without searching all the information.

In summary, first part is an equation that would search the information, but ignore the people I know but count the people I don't know giving me a number summarising the tasks I need to do something with.
The second part would be for excel to filter all those names onto a seperate sheet within the workbook giving me the details of their names for the unknown people so I can simply allocate those tasks without searching for them.

 

[Special-K99]

Ok, here's what I've done,

In column A are all the names, column B all the values, I've broken unknown into Fred 13 and Bert 11 as two names and values you dont know

In E1:E2 I've put Fred and Bert
In F1:F4 I've put the names you do know - in a random order (to ensure the order doesnt have to be the same).

for a total of names you do know
=SUMPRODUCT(--ISNUMBER(MATCH(A1:A6,F1:F4,0))*(B1:B6))
result = 42

for a total of names you dont know
=SUMPRODUCT(--ISNUMBER(MATCH(A1:A6,E1:E2,0))*(B1:B6))
result = 24