Using Templates and replace tags to create dynamic content

Hello, I am trying to create the subject text of an email message which needs to be sent to a user. The text will have some tags which need to be replaced with the appropriate values. Does anyone have some code / PHP class which they can share which would do the following: Template will be of the form: ************************** Dear __NAME__, Your current account number __ACCOUNT_NUMBER__ has a balance of __BALANCE__ as on __DATE__ Thanks, Administrator ************************** The code will be passed the template and a list of values which will replace the above tags __NAME__, __ACCOUNT_NUMBER___, ... If you need some clarifications, please contact me. Sending email is not a problem at all. I know this is not hugely difficult, but I am looking at some ready to use code, if possible. Thanks in advance. Regards, Sharat