InfoPath Dev

We are designing an InfoPath form template to control the input of outline-like data. To effectively provide the end users flexibility within this framework, users must be able to add, delete and reorganize the location of some portions of data. The form currently contains simple repeating sections that hold fields for data entry. Using an Expression Box with the fx [position() ] in each repeat section we can return the position number of each repeat section. The number output effectively works well to auto-populate a location of each instance of the repeating section for both our 1st and 3rd tier outline conditions but does not afford an option for an auto-populated A,B,C on the 2nd tier or i, ii, iii on the 4th tier. Are there any available InfoPath functions or moderately easy work-arounds to auto-populate a field or expression in a repeating section with a non-numerical logical data-type (A,B,C or i, ii, iii, iv)?

We are designing an InfoPath form template to control the input of outline-like data. To effectively provide the end users flexibility within this framework, users must be able to add, delete and reorganize the location of some portions of data. The form currently contains simple repeating sections that hold fields for data entry. Using an Expression Box with the fx [position() ] in each repeat section we can return the position number of each repeat section. The number output effectively works well to auto-populate a location of each instance of the repeating section for both our 1st and 3rd tier outline conditions but does not afford an option for an auto-populated A,B,C on the 2nd tier or i, ii, iii on the 4th tier. Are there any available InfoPath functions or moderately easy work-arounds to auto-populate a field or expression in a repeating section with a non-numerical logical data-type (A,B,C or i, ii, iii, iv)?