As others have noted, you are not limited to one argument in your translated string. Some examples:
One argument, in one place:
Mage::helper('module')->__('Hi %s, there is an error', $name);
Two arguments in two places:
Mage::helper('module')->__('Hi %s, there is an error with code %s', $name, $code);
One argument in two places:
Mage::helper('module')->__('Hi %1$s, there is an error. Your name is %1$s', $name);
Two arguments, places for exchange:
// Template or block file Mage::helper('module')->__('Hi %1$s %2$s, there is an error', $firstname, $lastname); // CSV translation "Hi %1$s %2$s, there is an error", "%2$s, %1$s received an error"
Documentation of the PHP function used to use it can be found here: vsprintf
(PS: The double quote that knase is talking about only applies to your CSV file, where the double quote is a single quote).
Tyler V.
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