I really want to use AutoIT to perform a search for lines beginning with a string and then replace the whole line with a substitute. (quickly for an entire file) In powershell I do it like this: $ComputerName = $env:COMPUTERNAME $FilePath = "C:\scripts\data.txt" $FindIT = "WorkstationID" $ReplaceIT = ("WorkstationID=" + $ComputerName + "stuff") #"----------------------" (Get-Content ($FilePath)) | Foreach-Object { $_ -replace ('^' + $FindIT + '.*$'), $ReplaceIT } | Set-Content ($FilePath) "cat the file to screen to see changes" "-----------------------------------------------" Get-Content ($FilePath) | foreach {Write-Output $_} in bash I do it like this, yes it's Linux but I need to do this type of thing in Windows: swap() #------------------------ swap function ------------------------------------------ # this little function is for a find and replace of lines starting with a string # first parameter is the file to be modified # second parameter is the line that begins with the string provided (all occurances) # third parameter is the entire line of data to insert in the place of second parameter { #echo first command line parameter (file name) is "$1" #echo second parameter (search for) is "$2" #echo third parameter (replace string) is "$3" if [ ! -f $1 ] then echo "A find and replace command was attempted against $1 but the file could not be found!" return else mv $1 $1"-temp1" varFind="$2" varReplace="$3" cat $1"-temp1" | sed -e "s,^$varFind.*,$varReplace,g" >> $1 rm -f $1"-temp1" echo "Modified $1 with $3" fi }; #-------------- end swap ------------------------------------------------------ How do I do this in AutoIT?