Ok, this is now resolved [in a fashion]

What I'm doing is passing the file location parameter to a .bat file

So I have my .bat file OracleSQL.bat which contains this code:

@echo off
sqlplus @%1
exit;

I can now shell out to the batch file with the file parameter:

Dim strBatchName As String

strBatchName = "C:\location\of\bat\OracleSQL.bat Z:/aFolder/aScript.sql"
Shell strBatchName

Done :)