Complex formula question

[diverdown87]

Not sure really where else to turn.
I have a spreadsheet where I need to calculate days past in one column but the rub is I need variables from a second column factored in.

Here is an example of what I mean:
I have a column A that shows a possible one of 3 criteria: Critical, Severe, and High. Each one of these has a different time value 15, 30, and 45 days respectively. These values and criteria cannot be moved from this column.

Column B has a date that the entry was created

Column C is the Days Past column that will need to be populated with the complex formula. (If it can be done)



To throw a bigger monkey wrench into the mix is the fact that the entries that have not gone past the time as a negative (indicating it has not reached the due date yet according to column A criteria)

Thanks for taking a look and Ihope someone can assist with this or even just tell me Nope can't be done without different columns for the Critical, Severe, and High parts.