Access to version string from inside .ism (passed as IsCmdBld.exe -y "1.0.0")

[capcob]

I am completely new to InstallShield but have inherited a fully working script running on a build server- on the face of it this seems like a trivial task.

What I want to do is update setup .msi and .exe file names to include product version string supplied as follows eg IsCmdBld.exe -y "1.0.0"

So I have tried to change the name setup_x64 in the properties table below to include what is passed to IsCmdBld.exe and end up with eg setup_1_0_0_x64.exe or setup_1_0_0_x64.msi, but without success -
any attempted substitution eg setup_[PRODUCT_VERSION]_x64.exe is simply treated literally at IsCmdBld.exe run time.... what do I need to do here ?

ISProductConfiguration_	Property	Value
s72	s72	L255
ISProductConfigurationProperty	ISProductConfiguration_	Property
PROJECT_ASSISTANT	IncludeActionHelp	1
PROJECT_ASSISTANT	MSIPackageFileName	setup_x64
PROJECT_ASSISTANT	SetupFileName	setup_x64

Any help here much appreciated !

[capcob]

I can do it in WiX and NSIS no problem and they are free !