Can anyone translate this bunch of C into VB?

I'm having some difficulties.....

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NotifyCallbackHandler((struct NotifyCallbackRecord *)lParam);
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I know this calls a function "NotifyCallbackHandler",
but what is the VB equivalent of:
(struct NotifyCallbackRecord *)lParam);

I already have a Type def as the VB version of Struct, and it's created to match the C struct.

I've tried this:
RtlMoveMemory pCallBackRecord, lParam, LenB(pCallBackRecord)

Any help?