Executing KSH batch file located in specific folder

Ok apologies if this is trivial or doesn't make sense but I am quite new to korn shells;

So I have a .ksh batch file located in a folder of my choosing, I want to run this file in a korn shell.

The problem though is that I want to get VBA code to do this. I have (VBA) code which opens command prompt (cmd.exe) and runs a (one) command line.

So far I can get the kornshell to open, using the command line; "C:\\WINDOWS\\system32\\POSIX.EXE /u /c /bin/ksh -l". This opens the korn shell in a default directory. I guess I need to add to this line to get it to then go to the specified folder (which i obtain from the VBA code) and execute the batch file.

Looking around on the web I got the code below, but I can't get it to work; "C:\\WINDOWS\\system32\\POSIX.EXE /u /c /bin/ksh -l -c \"cd \\\"`chgpath -p '%L'`\\\";ksh\""

Any help would be greatly appreciated.
(Also could someone explain to me what each part of the above command actually does)

Thanks Chris

I've never used ksh in a Windows environment but can't you just include the full path to the script on the command line?

"C:\\WINDOWS\\system32\\POSIX.EXE /u /c /bin/ksh full_path/script.ksh"