Have a program I would like to silently install though would like the ability to install from it's own Dir without the need to specify it path or location for install?

If I install from the root of C installs no problem.
Manufacturer recommends installing as eg
C:\"Mick.exe" /s /v"SERIAL=000000000000" -f1"C:\setup.iss"
Any pointers from any scripting dudes is appreciated?