You could use the ReadFile() UDF to read the entire file into an array, then do a check to see if there is a line with the username in the array, set the value of that specific array element to the values you want and write the entire array to a file.
Don’t forget to include the ReadFile() UDF in the code below.

Something like this (example below is untested!):
 Code:
Break on

$file = readfile("c:\file.log")

For $i = 0 To UBound($file)
	If InSTR($file[$i], @USERID)
		$file[$i] = "Some new text here"
	EndIf
Next

$rc = Open(1,"c:\newfile.log", 5)

For $i = 0 To UBound($file)
	$rc = WriteLine(1, $file[$i] + @CRLF)
Next

$rc = Close(1)
Move "c:\file.log" "c:\oldfile.log"
Move "c:\newfile.log" "c:\file.log"
_________________________
Mart

- Chuck Norris once sold ebay to ebay on ebay.