Calling CertEnumStoreStore callback C++ function in C#

Question

In C++, calling this function is just as simple as:

CertEnumSystemStore(CERT_SYSTEM_STORE_CURRENT_USER, NULL, NULL, (PFN_CERT_ENUM_SYSTEM_STORE)addr);

Addr would just be the base address of where the function resides

In C#, you can't just pass in an address, and will have to pass in a function, which is not what I want in this case. Below is a snippet of my code

public delegate bool CertEnumSystemStoreCallback([In, MarshalAs(UnmanagedType.LPWStr)] String pvSystemStore, uint dwFlags, ref CERT_SYSTEM_STORE_INFO pStoreInfo, uint pvReserved, [In, MarshalAs(UnmanagedType.LPWStr)] String pvArg);

[DllImport("crypt32.dll", CharSet = CharSet.Unicode)]
public static extern uint CertEnumSystemStore(uint dwFlags, uint pvSystemStoreLocationPara, String pvArg, CertEnumSystemStoreCallback pfnEnum);

[StructLayout(LayoutKind.Sequential)]
public struct CERT_SYSTEM_STORE_INFO
{
   uint cbSize;
}

CertEnumSystemStore(CERT_SYSTEM_STORE_CURRENT_USER, 0, null, (CertEnumSystemStoreCallback)addr);

I get a type conversion error that tells me it can't cast type InPtr to type CertEnumSystemStoreCallback.

What can I do to just pass an address containing the function instead of having to supply the function name itself?