Antimatter - Matter collision in my head

[kedaman]

I have this UDT system:

Private Type word
    str As String 'The part
    counter As Long 'The probability counter
    Constant As Boolean 'Constant flag
End Type
Private Type wordcollection
    word() As word 'Dynamic word array
    counter As Long 'Overall probability counter
End Type

'the propability of occurance of a word is:
Probability counter / Overall probability

Now i need a procedure that picks out a word from a wordcollection using RND function. But its antimatter - matter in my head so I can't figure out how to do this.

Can someone help me?