Since you say the first string works opening the cash drawer, just try the three question mark solution with the text you want with your Epson printer set as the default.
??? "First line - $10.24"
??? "2nd line - $3.25"
The ??? only needs to be followed by a legitimate expression.
??? Command
http://msdn.microsoft.com/en-US/library/f5c41twb(v=VS.80).aspx