Initialization in SAP Query For country key in WHT report

[acetedi]

Hello everyone, iam working on alv report but i need syntax on fields country key need already input when user enter the program like this picture

when user enter inputing output group, reporting period, company code and fiscal year. and click enter

on field "Extended WH Tax Type" filtering data from country key "ID" like this picture

any hints or help would be appreciate and correct answer will be reward!!

Thank You