如何将XAML中的DatePicker和TextBox信息转换为Powershell变量？

I am new to scripting (first year) and this is my first time trying to take a WPF application from VisualStudio and turn its XAML code into something that I can use with Powershell. I'm attempting to create a small application that will allow me to enter an Active Directory username into a TextBox field and select a date from a DatePicker object and then turn both of those pieces of information into Powershell variables. From there, I enable VPN access for the AD user and then use the date as a "cutoff date" at which point I will disable the user's access. Both of those variables will also be outputted to a .csv file on our server that will be read daily by a Scheduled Task. If the cutoff date matches the current day, another script will be triggered that disables the user's VPN access. (That scheduled powershell script is not included here and will be written later.)I am new to scripting (first year) and this is