You can one data structure to another using the API RTLMemory function. This is typically declared as CopyMemory as follows:

Public Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Any, Source As Any, ByVal Length As Long)

In your case the destination is the pointer to the string obtained using strptr and the source is the UDT obtained using varptr. Remember to use LenB function to obtain the length of data to be copied.

HTH,
SUN.