I presume you are looking to increase the numeric value of a text string by a user defined number? I don't know if this can be done, because you would need to convert each string value into a real number before adding your new value to it. The result would then need to be converted back into a string before being passed back as an updated entity. Although I know you can convert real-to-string I don't know about the other way. Also, if any of the level strings included non-numeric text, for instance '145.354 IL' you'd also have to deal with stripping out these elements and putting them back in after. If my interpretation of your problem is correct I can't really think of a solution that would do it.