Tony,
Use the Val() expression in TestStand. For example, Locals.X is a string, Locals.Y is a number.
Locals.X = "2A",
Locals.Y = Val("0x" + Locals.X)
At this point, Locals.Y is now 42. You can choose to display this as 2A or 42, depending on your formatting options. In any case, it represents the same number- the integer 42.