Skip dialog box "Execute/Cancel" when starting MS-Dos batch file

Hello All,

I am running Windows XP SP2
We have some legacy apps running on our network that are started up from a
batch file.
When I start up the app, a dialog box appears saying (translated from
Dutch):

Cannot confirm publisher. Are you sure you want to run this software?
Name: ps.bat
Publisher: Unknown Publisher
Type: MS-DOS batch file
(started) from: U:\pscfg

I know there is a trick to skip this dialog box, so I do not have to click
it every time I start up the software
Does anyone here know what that trick was?
I thought it was a registry hack, but I'm not sure

TIA
Peter-Paul Jansen
Rijswijk, The Netherlands