Subtract times in text

[neelsfer]

I use this timing application.
A client asked me to add a feature. The athletes run without watches and before the race each one has to give an estimated or expected time they would finish the race. The one with the closest to the actual time wins.
I subtract the finishtime from the starttime to get actual racingtime. Then i subtract the Expected time from this actual racingtime.
It must then be sorted to the one closest to the actual time.
Calculating the difference between the finish and starttimes is easy, but the last part is giving me grey hairs.
The code used to calculate the actual racingtime in query

RacingTime: Format([TimeFinish]-[TimeStart],"hh:nn:ss")

i think the problem is because the (estimated) expected time is captured in a text field.
i tried this in query

TimeDiffs: Format$(IIf(IsNull([Racingtime]-[ExpectTime]),0,CDate([Racingtime]-[ExpectTime])),"hh:nn:ss")

i attach an example of this. Go to view results button please.
i will appreciate help

[ADezii]

Give the following Statement a Test Run:

TimeDiff: Format(([TimeFinish]-[TimeStart]) - CDate([ExpectTime]),"h:nn:ss")

[neelsfer]

Mr Adezi, what can i say? - it works 100% as usual. Thx