Simplest Method For SQL Insert

I have spent the afternoon researching this, and to no avail so here's my question.

I have a user input form with upwards of 60 fields that are to be filled in by the user (intranet environment).  I want to post those values as a new record in an SQL database.   I have setup an SQLDataAdapter tied to a parameterized stored procedure on the SQL server.   I can successfully post data from the controls on the form when I set the parameter type to Control based.

Here's the problem, though.  I need to do some pre-processing on most of the values in the controls on the form.  I have setup VB code (that executes when the user clicks the "Submit" button), that pulls in each control value, performs any necessary processing, and sets a variable to the value I actually want stored in the DB.  How can I assign THAT value (from the variable) to the parameter for the stored procedure?  

Thanks,

Dave