Unusual Weight Calculation Help

[LEVICC01]

Hi,

I've spent hours trying to solve this myself, and feel really dumb that i cannot sort it. I cannot use an Add in, but instead need a formula to look at just the figures, and then convert it and im now braindead... Any help would be appreciated.

The format needs to be input as shown in the second column

I have 4 columns:

These are not Decimals which is why i'm struggling, this is input as 14 Stone, 13 Pound.

I need the difference column automated.

Please help.

Date Starting Weight (Stone/Pound) New Weight Difference
11/05/11 18.13 17.08 -1st.4lb
18/05/11 17.08 14.11 -2st.12lb
25/05/11 14.11 13.06 -1st.5lb
05/06/11 13.06

 

[shg]

      -----A----- --B-- --C-- --D--
  1      Date     Start  End  Delta
  2   11 May 2011 18.13 17.08 -1.05
  3   18 May 2011 17.08 14.11 -2.11
  4   25 May 2011 14.11 13.06 -1.05

The formula in D2 and down is

=DOLLARFR(DOLLARDE(C2,14) - DOLLARDE(B2,14), 14)

 

[LEVICC01]

This is pefect... i would have never worked that out myself ha ha ha.

Thank you!