I wish to compare the cost of telephone calls between various telephone
service providers available to me.
I have downloaded a list of itemised call made by me from my present
provider and I wish to compare the cost of each call if I had used
alternative providers.

I'm OK with the basic mathematical formulae - but I need to convert a "Call
Duration" in "hh:mm:ss" format to seconds.

(I could use the "Text to columns" facility and then multiply the " Minutes
Column by 60 and the hours column by 360 - and add the three columns together
but feel this is clumsy when there must be a "nicer - easier way)

Thanks for your help.

Ian M