Go/CGo - how do you use a C array passed as a pointer

I'm posting this as a question/answer, as it took me a while to work out, and I wouldn't mind some feedback on my solution. In Go/CGo, how do you work with a C array passed as a pointer?

For example, with this C struct:

struct _GNetSnmpVarBind {                     
    guint32     *oid;       /* name of the variable */
    gsize       oid_len;    /* length of the name */
    ... and other fields
};  

I want to convert oid field to a Go string, how would I work with the guint32* pointer?