Delphi Dual list dialog box

I have developed a Dual list Dialog box that populates the leftside memo with the column names from a string grid object, what I want to do is when the user has moved the appropriate values to the right and clicked ok I need to be able to determine the column number from the string grid that the selected values come from. I obviously know the column's name but I don't know where this column is located in my string grid. Does anyone have a good suggestion on how I might easily keep track of this if possible.

For example if the column heading is Fruit, I need to know where in the string grid the column with the first row title of 'Fruit' exists for arguments sake let's say this is column number 2 in the string grid. I will then read through the remainder of column 2 to rowcount and perform my calculations.

Thanks

Jake