counting common data and further split with pre-determined ratio by country with a specific ID code

I have a sample file attached where the column description as follows -

column-A: a unique group of data, when counted it gives value of 78

column-B: Identifier for specific ID of group to map the reference table on column F to H.

column-C: is the results should appear when dragged or any automated way to populate the result.

the method or rule user story as follows -

coulum-A cells should be counted and outcome counted number is referenced with Identifier code.  next step the identifier code has split ratio of 10% to UK and 90% to US.  It should split that total count value and populate the column-C with each split value as result with country name.