If you want full configurability, you can use this version: Calc.zip
By using Decimal_Sign you can change it in the ini, and for stuff you normally need the , for, you can use the point. (so pow(2,4. 3) instead of pow(2.4, 3))
The Calc-features was the first thing I tested since I have had problems with those plugins in Launchy. And since I'm swedish this configuration was my first stumbling point, it is needed to allow for our decimal comma. So many thanks for this patch!
Minor thing though, replacing the already used instances of comma with period is not the best option, it just looks wrong. Instead you should use the same approach as swedish Excel/VBA formulas and use semicolon for separating arguments, or at least make it configurable.