IF Formula in Numeric ( Selected Currency )

Hi Manny , Thanks for helping me out 

So basically I want the Total Amount Price is in total from either currency "AUD" or "Euro" with the exchange rate calculation already. 
Total Estimate AUD : Formula-Numeric   --> [qty]*[price AUD] 
Total Estimate Euro : Formula-Numeric   --> [qty]*[Price Euro]

Total Amount Prince : 
If currency "AUD" then calculate Total Estimate AUD * Exchange Rate , 
else currency "Euro" then calculate Total Estimate Euro * Exchange Rate 

I tried with this formula but didnt work. Any idea whats the best way to do with the formula ? 
I hope I explain it clear , I am only beginning with the formula functions. 



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