Hello, Here is the replaceregexp call: As you can see I wrote the regular expression: * (?<=\#\[SYD\-DATASOURCE\]\s)disabled\s=\sfalse* To match text like the following: *...... (line break) #[SYD-DATASOURCE] disabled = false ...... ...... * When testing this regular expression out in a testing tool (Regex Creator) I found that the positive lookbehind matched *"disabled = false"* perfectly. But ANT does not properly replace *"disabled = false" *with *"disabled = true"*. Is the < throwing ANT off or is there another reason why the positive lookbehind is failing? Thanks in advance, Tony