TestComplete should have project suite parameters so that we can send our required parameters and we can call specific control.
Several ways of doing this. Something I've done in the past is created an INI file and then used the "Storages.INI" object of TestComplete to parse the file and populate project and project suite level variables for use in the specific test run. Any time I need to change the parameters, I just edit the INI file.
Another way of doing it is to parse the commandline (if you're running via command line) to look for custom parameters. I have a script extension that I've encapsulated that code into. I need to make sure it's compiled correctly. If it looks good, I'll give you the link to download so you can utilize this methodology.