Here's a way to automate this a little (one click updates the rate):
The script below will place the Yahoo! Finance rate in the target cell here C1.
Copy into AppleScript Editor, click somewhere in table, click green triangle "Run" button.
SG
--click anywhere in table, run; places exchange rate in target cell
property targetCell : "C1"
property symbol : "eurchf=x" --> Swiss Francs per Euro
set sourceText to do shell script "curl -s http://finance.yahoo.com/q?s=" & symbol
set extractedText to extractBetween(sourceText, "yfs_a00_" & symbol & "\">", "</span>")
return placeValueInCell(extractedText, targetCell)
--handlers:
to placeValueInCell(theValue, targetCell)
try
tell application "Numbers" to tell front document to tell active sheet to tell ¬
(first table whose class of selection range is range) to set ¬
value of celltargetCell to theValue
on error
display dialog "Did you select a table?" buttons "Cancel" default button "Cancel"
end try
end placeValueInCell
to extractBetween(sourceText, startText, endText)
set {oTID, AppleScript'stext item delimiters} to {AppleScript'stext item delimiters, startText}
set endItems to text of text item -1 of sourceText-- everything after startText
set AppleScript'stext item delimiters to endText-- get ready to split endText
set textInBetween to text of text item 1 of endItems-- take everything before endText
set AppleScript'stext item delimiters to oTID-- restore original values
return textInBetween
end extractBetween
--end of script