Why do you need to have an iScript to front this???
If the reason is to initiate it through the browser, you could also create an Application Engine that calls the bat file using the Exec function that initiates the sqr.
You can call the application engine to execute straight from PeopleCode, not over the process scheduler using the CallAppEngine function
PeopleBooks: Description* Use the CallAppEngine function to start the Application Engine program named applid. This is how to start your Application Engine programs synchronously from a page. (Prior to PeopleTools 8, you could do only this using the RemoteCall function.) Normally, you won’t run Application Engine programs from PeopleCode in this manner. Rather, the bulk of your Application Engine execution will be run using the Process Scheduler, and the exception would be done using CallAppEngine
When you run the application engine directly from peoplecode using the CallAppEngine function the Exec function will look for the bat file in PS_HOME of the application server.
Portion of PeopleBooks on Exec:
+Exec(command_str [, parameter])+ where parameter has one of the following formats: Boolean constant Exec_Constant Path_Constant+
Using an Absolute Path If you do not specify anything for the second parameter, or if you specify a Boolean value, the path to PS_HOME is prefixed to the command_str. If you specify constant values for the second parameter, PS_HOME may or may not be prefixed, depending on the values you select. You can use the GetEnv function to determine the value of PS_HOME.
See the Exec function in PeopleBooks with a lot of example on how you use this with different path types.