popup message in a batch file

I am creating a batch file that actually copies a couple of files to all client computers, runs an msi fileto upgrade the citrix ica client. the upgrade will fail if the client is in use so i am using pskill to kill the process before the .msi runs. to make sure the client does not reopens the ica client i want to display a message on the client computer in a window for some 5 minutes and automatically close the message after 5 minutes.  my script looks like this

@ECHO OFF
cd\
md tools
cd tools
xcopy \\computer name\folder\tools\*.* c:\tools
pskill -t wfica32.exe
pskill wfcrun32.exe
sleep 10
start "" \ \\computer name\folder\webcustom.msi

i want the following message to be displayed as a message box and automatically close after 5 minutes

Computer department ------as the title
Citrix ICA client upgrade in progress, Please do not open any citrix application
after 5 minutes this message should close

i am already copying tools like sleep and pskill so we can copy an additional tool also which can display a message. need this urgent please



citri