Try this in a code module, and use in formula

Code:
 
Function ACRONYMIZE(rng As Range) As String
    Dim lng As Long
 
    For lng = 0 To UBound(Split(Trim(rng.Text), " "))
        ACRONYMIZE = ACRONYMIZE & Left(Split(Trim(rng.Text), " ")(lng), 1)
    Next lng
 
End Function
Example = ACRONYMIZE(A2)