Launching an application with a PS script

Question

Hi everybody,
          I'm an absolute beginner with PowerShell, so please be patient :-)
I'm going to write my first script for PowerShell. The script core concerns an external software I need to launch. This is a typical code for a batch file:
cd case_path
echo "macro" | "app_path"app.exe case.ext 2>&1 >> log
It results in:
- go to the folder containing the 'case' to launch (just a file containing settings)
- run the case with application.exe, execute the 'internal macro' and generate a log file
I'm able to run the application with
Invoke-Item app_path\app.exe
but I can't run the specific case (and the internal macro too). Could you help me, the batch script as a starting point?

Answer 1

OK, I'm here again, just for feedback and sharing (are there other newbies out there?)
I made some tests with both methods (thanks Fred and jrv!).
method cmd /c
$FS_path = $env:fsinstall + '\bin\win32\'
$case_path = '.\f1'
$cmdString = 'cd ' + $case_path + ' && echo "res" | "' + $FS_path + '"xfsflow doubleSkegCase.fme 2>&1 >> log.txt'
method Start-Process
$FS_path = $env:fsinstall + '\bin\win32\xfsflow'
$args = '-c "res" doubleSkegCase.fme'
$FS_case = '.\f1'
$sim=@{
FilePath = $FS_path
ArgumentList = $args
WorkingDirectory = $FS_case
RedirectStandardOutput = "$FS_case\log.txt"
Start-Process @sim -noNewWindow -wait
just two more questions:
1. is it possible to get rid of the standard error output? I'd like to have no error messages in the terminal or as a file
2. I'd like to make the macro "res" in the ArgumentList
as a variable, but I'm not able to. I guess the problem concerns escape characters or similar, could you help me?