Sure.
Here’s an example that kills notepad.exe. Internet Explorer would be iexplore.exe.

 Code:
Break on

$process = "notepad.exe"

$rc = KillProcess($process)

If $rc = "0"
	?$process " successfully stopped."
	?"Error code: " $rc
Else
	?$process " NOT successfully stopped."
	?"Error code: " $rc
EndIf
Sleep 5

;DO NOT MODIFY ANYTHING BELOW THIS LINE.
;THIS IS A UDF AND IT COMES READY MADE.
;
;Function	KillProcess() - Kills the Process specified
;   
;Author		Arend Pronk (apronk on the forum)
;   
;Contributors	Chris S. (based on his ProcessMon)
;    		Radimus (his suggestions to change some code)
;   
;Action		Kills the Process specified and returns a 1 for success or 0 for failure  
;   
;Syntax		KillProcess($sProcessName,Optional $sComputer)
;    		Where $sProcessName is the name of the process you are trying to kill
;    		and $sComputer is the name of the computer to kill the process on.
;    		If no computer is specified it is done on the local computer.
;    		Remote computers require this script to be run as an admin of the remote computer 
;   
;Version  	1.0  
;   
;Date		2006-Jan-27 
;   
;Date Revised	2006-Jan-29   
;   
;Revision Reason
;    		Revised per Radimus's suggestions.
;   
;Returns  	0 for success, Errorlevel for failure  
;   
;Dependencies	KiXtart 4.02 Recommend 4.51 or newer 
;   
;KiXtart Ver.	Written and tested with KiXtart v4.52 Beta 2 on Windows XP/2003  
;   
;Example 
;		Dim $KP 
;		$KP = KillProcess("notepad.exe") 
;		If $KP = 0 
;		  ? "Process killed succesfully!" 
;		Else 
;		  ? "Process killing failed!"
;		EndIf 
;   
Function KillProcess($sProcessname, Optional $sComputer)
  Dim $objWMIService, $objInstance, $colItems, $objItem, $strWBEMPath
  If $sComputer = ""
    $sComputer = "."
  EndIf

  $objWMIService = GetObject("winmgmts:\\" + $sComputer + "\root\cimv2")

  If @ERROR
    Exit @error
  EndIf

  $colItems = $objWMIService.ExecQuery("Select * from Win32_Process",,48)

  For Each $objItem In $colItems
    If $objItem.Name = $sProcessname
      $strWBEMPath = "Win32_Process.Handle=" + $objItem.ProcessID
      $objInstance = $objWMIService.Get($strWBEMPath)
      $KillProcess = $objInstance.Terminate(1)
    EndIf
  Next
  Return $KillProcess
EndFunction


[edit]
Beware that killing iexplore.exe will kill ALL internet explorer windows.
Iirc there is a UDF that closes the app you specify but I'm not 100% sure.
You could have a look in the UDF section and browse through the listed UDF's.
[/edit]


Edited by Mart (2008-07-14 05:25 PM)
Edit Reason: Added warning.
_________________________
Mart

- Chuck Norris once sold ebay to ebay on ebay.