GapTimeNext(resultID;rankID;text last;time format) calculates the gap time between a participant and the next participant. The resultID determines which result to consider; the rankID determines who is the next athlete; text last is the text to show for the last athlete; and time format specifies how to format the gap time. For example:

GapTimeNext(1;3;"--";"+m:ss,kk") 

Using the default Results (Result ID 1 = Finish Time) and Ranks (Rank ID 3 = AGRank) this would return the time ahead of the next runner, in the same age group, based on finish time. 

The third and fourth parameters can be omitted. "-" and "+HH:MM:ss,kk" are the default values.