Well, as I mentioned, it gets messy...

The problem here is that you have to consider this a multi step process.

1) You have to get the letter by itself.

2) You have to do two things with the letter. You have to translate it into its numerical equivalent AND create a another column (variable, whatever) as 1 or -1, depending on the A-I vs. J-S location.

3) You have to append the numerical equivalent back onto the tail of the string for the rest of the number. You then convert that string to numeric (x,2) and then divide it by 100, to get your decimals.

4) Finally, multiply the result from 3 by your 1/-1 variable/column you found in 2.

Don't try to do this all in a single step, you'll drive yourself absolutely batty if you ever have to maintain it. If you're not looking to use the .NET transformation script component, then I'd recommend using multiple derived columns in the stream, chaining off each other. First one would split out your two pieces of the amount string, next one would derive the # and the multiplier, third one would concatenate the values and convert to numeric, the final one would apply your division and use your multiplier.