When you load the xla, two functions are added:
DFTOS (Decimal Feet to Standard) =DFTOS(YourDigitalMeasurement) and
STODF (Standard to Decimal Feet) =STODF(YourStandardMeasurement)
( It should be notedthe standard feet measurements (such as 12' 9") cannot
be summed; xl sees
them as text; you have to sum as decimal, then convert.