Event Study

I have a dummy variable for currency crises occurrence and I want to create a variable as below (newvar) with pre- and post crisis-numbers:

Country CurencyCrises newvar
Argentina 0 -2
Argentina 0 -1
Argentina 1 0
Argentina 0 1
Argentina 0 2
Argentina 0 3
Argentina 0 -3
Argentina 0 -2
Argentina 0 -1
Argentina 1 0
Argentina 0 1
Argentina 0 2
Brazil 1 0
Brazil 0 1
Brazil 0 2
Brazil 0 - 1
Brazil 1 0
Brazil 0 1
Brazil 0 2
Brazil 0 - 2
Brazil 0 -1
Brazil 1 0
Brazil 0 1
Brazil 0 2

I want to create this variable in order to plot mean of international reserves and check whether reserves are lower during the crises or pre-crisis.