Let's say you want to send money with through my agency.
I will get 0.05 on every dollar.
That is if you send \$100 dollars, should get 0.05 on each of the dollars in the \$100.
I am doing this $100 \times 0.05 = 5$.
How can I apply this to other currencies like Euro, or Australian dollar for example? Let say you decide to send money using Euro or other currency?
You do the exact same thing. If you take five cents out of every dollar, then you also take five (euro-)cent out of every euro, and five pennies out of every pound. You take $5\%$ (i.e. multiply by $0.05$, as you did above) of anything sent through your agency, regardless of what currency is used.