Here's what finally worked. I created several variables on my report, detailed below:
(Probably this will only work for when the days between is 0 or 1, I only did it for when the start and end date were the same, or the start and end date spanned the midnight hour... my data won't ever be otherwise)
DaysBetween:
=DaysBetween(ToDate(FormatDate(<Audit Start Dt> ,"mm/dd/yyyy"

,"mm/dd/yyyy"

, ToDate( FormatDate(<Audit End Dt> ,"mm/dd/yyyy"

,"mm/dd/yyyy"

)
SecondsElapsedTime:
=ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,1 ,2))*3600+ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,3 ,2))*60+ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,5 ,2))-(ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,1 ,2))*3600+ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,3 ,2))*60+ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,5 ,2)))
SecondsAfterMidnightStart:
=ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,1 ,2))*3600+ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,3 ,2))*60+ToNumber(SubStr(FormatDate(<Audit Start Dt> ,"HHmmss"

,5 ,2))
SecondsAfterMidnightEnd:
=ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,1 ,2))*3600+ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,3 ,2))*60+ToNumber(SubStr(FormatDate(<Audit End Dt> ,"HHmmss"

,5 ,2))
ElapsedTimeOverMidnight:
=86400-<SecondsAfterMidnightStart> + <SecondsAfterMidnightEnd>
Elapsed Time:
= If <DaysBetween> = 0 Then FormatNumber(Truncate((<SecondsElapsedTime>/3600) ,0) ,"00"

+ ":" + FormatNumber(ToNumber(FormatNumber(Truncate((<SecondsElapsedTime>/60) ,0) ,"00"

- ToNumber(FormatNumber(Truncate((<SecondsElapsedTime>/3600) ,0) ,"00"

) *60) ,"00"

+ ":" + FormatNumber(Mod(<SecondsElapsedTime> ,60) ,"00"

Else FormatNumber(Truncate((<ElapsedTimeOverMidnight>/3600) ,0) ,"00"

+ ":" + FormatNumber(ToNumber(FormatNumber(Truncate((<ElapsedTimeOverMidnight>/60) ,0) ,"00"

- ToNumber(FormatNumber(Truncate((<ElapsedTimeOverMidnight>/3600) ,0) ,"00"

) *60) ,"00"

+ ":" + FormatNumber(Mod(<ElapsedTimeOverMidnight> ,60) ,"00"
Next hurlde will be to ADD UP the elpased time so I get a total for each 'section'. (By Nursing Station, by charting session, etc.).
Any ideas?