index sorting by numbers with decimal points

[Phoenix Hummel]

Using FM 9.2.
 
Is there an easy way to sort numeric index entries with decimal points...? As the reference page exists, my numerics are sorted according to the number appearing as the first number to the left of the decimal point - that results in my numbers not sorting correctly. For example, 9.3 appears after 750.350 because 9 is larger than 0. My current fix is to pad with zeros the numbers in my marker box by following the actual marker text with brackets enclosing the number to be sorted with the padded zeros. For example, 750.350[75000350] and 9.3[90000003]. My books contain up to 100 legal statutory references and this process is tedious and incredibly time consuming. Any ideas?