I have a df `TRX` with pairs of Date and Curreny

```
Date            Currency      ExchangeRate
2012-08-13      EUR           ?
2012-08-13      CHF           ?
2012-08-13      CZK           ?

```

I have a second df CURRENCIES for the currency conversion rates with EUR base. 

```
Date            EUR    CHF       CZK
2012-08-13      1      1.24      25.73
2012-08-13      1      1.23      25.92
2012-08-13      1      1.22      24.00

```

Now I want to translate the day rates. I wrote a function for this liske
getDayRate(date,currency).

```
getDayRate <- function(date, currency) {
currencies[which(as.character(currencies[,c("Date")]) == date),c(currency)]
}

getDayRate("2013-06-20","EUR")

```

Now I want to apply `getDayRate(date,currency)` to each row of `TRX` so that for each row it uses the first and second element as arguments so I get teh `ExchangeRate`.

`apply(x,1,fun())` does not work as it requires a matrix with numbers. In theory i would have to convert the dataframes to the indices and then use apply.

Is there a better way?