Within 'Stage-Probability Mapping' I have a numerical value ('Probability' the deal will come through) thats dependant on the value of another variable ('Stage' of the deal). IE:

Stage = 1. Opportunity, Probability = 10%

Stage = 2. Scope Agreed, Probability =  15%

Stage = 3. Sent Proposal, Probability = 20 %

etc...

This is great. However, sometimes I want to manually insert a different value for 'Probability'. I will naturally feel more confident of closing certain deals. How can I manually insert a figure for a value thats been created within 'Stage-Probability Mapping'?

Any answers are much appreciated.

Bobby