I've written a small program in Java that reads data from an Excel sheet does some processing and writes the results to a database. It would be extremely convenient to be able to launch the JAR file from Excel. Does anyone know if this is possible and if so how it could be accomplished?

I am importing a bunch of data which is all in varchar format which I cast into the relevant type on transfer to the production table. One of these columns contains decimals, but some of them are occasionally given in scientific notation (3.48E-02).
I am using

CAST (v1 AS decimal(18, 13))

to do the conversion, but that seems to be unable to handle the scientific notation. Does anyone know a way around this?