Occurrences of specific values to a Straight Table

[#1]

Suppose I have a long table:

Usertable:

User	Country
john	UK
jack	SG
jane	UK
joey	ID
joel	FR
jess	UK
jill	DE
josh	FR
joos	NL

And I'd want a little Straight Table next to it showing this kind of sums.

Summary of key countries:

Key_country	Users_in_there
UK	3
SG	1
FR	2

For this summary table the countries to be considered are pre-defined, i.e. the list Key_country comes from a different table, to prevent all countries occurring in the Usertable from showing in the summary

What should I have for the Users_in_there expression to get the counts highlighted with red? In 'pseudocode' it mean it to be something like this:

     = number of occurrences of Key_country in field Country

[#2]

try to use

=if(match(Key_country,Country)=1, Key_country)

as a dimension