Lambda as a param of UDF

A Lambda can take an input (parameter) that is another Lambda. Likewise, I would assume that I can supply a Lambda into a UDF in VBA that expects "Lam As Variant" (since normally anything goes with a Variant).  Does anyone know how I might invoke this "Lam"?  (I notice that eg "Lam as Lambda" is not a recognized syntax.)

Thanks for your help.