need help with 7-zip functionality

[Nights]

hey im new here and new to vb.net iv worked alot in batch scripting and i LOVE how this peice if code works... but cant get it to work in vb.net ... i remarked above each line to explain what each line does.. help me plz i have ALOT of programs that run this way... and id love to have a VB.net exe that does it insted of a batch...

::Extracts to the environment variable for TEMP directory

start /wait Programs\Optimize\AusLogics_Defrag.exe -o%TMP% -y -Pthisisthepass

::Runs the exe with command line arguments

%TMP%\AusLogics_Defrag\cdefrag.exe -dt -o c:

::Once its done it deletes the extracted folder and its contents

IF EXIST "%TMP%\Auslogics_Defrag\" (RMDIR /S /Q "%TMP%\Auslogics_Defrag\")