It's a little complicated, as you have to set registry keys.
Assuming that you have a full version of Adobe Acrobat that has installed the initial registry keys:
First, you have the registry accessing functions, which you put in a non-sheet module:
Private Const HKEY_CURRENT_USER As Long = &H80000001
Private Const HKCU = HKEY_CURRENT_USER
Private Const KEY_SET_VALUE = &H2&
Private Const REG_SZ = 1
Private Declare Function RegOpenKeyEx Lib "advapi32" _
Alias "RegOpenKeyExA" ( _
ByVal hKey As Long, _
ByVal lpSubKey As String, _
ByVal ulOptions As Long, _
ByVal samDesired As Long, _
phkResult As Long) As Long
Private Declare Function RegSetValueExA Lib "ADVAPI32.DLL" _
(ByVal hKey As Long, _
ByVal sValueName As String, _
ByVal dwReserved As Long, _
ByVal dwType As Long, _
ByVal sValue As String, _
ByVal dwSize As Long) As Long
Private Declare Function RegCloseKey Lib "ADVAPI32.DLL" ( _
ByVal hKey As Long) As Long
Then, you use the following code to set the registry key that tells Adobe where to save the file. Note, it has to be set everytime you print.
Dim RegResult As Long, Result As Long
RegResult = RegOpenKeyEx(HKCU, "Software\Adobe\Acrobat Distiller\PrinterJobControl", _
0&, KEY_SET_VALUE, Result)
RegResult = RegSetValueExA(Result, "C:\Windows\splwow64.exe", 0&, REG_SZ, _
FileName, Len(FileName))
RegResult = RegCloseKey(Result)
Also Note, the "C:\Windows\splwow64.exe" is what I needed for my Excel 2010 32-bit, and it may be different for you. To determine it (which won't change) first print manually to PDF, then go to the registry key and see what application is used in the HKCU\Software\Adobe\Acrobat Distiller\PrinterJobControl LastPDFPortFolder key. Then use the name of the full application path for that executable.