Dave,
you seem to have tried most ways to get your 200-column table to work and I
have no further suggestion as to how make this work. But have you
considered the possibility of reducing the number of columns and rather
increase the number of records?

E.g. rather than having

ID Price VAT% VATAmount Sum (and another 200 columns)
1 100 24 24 124
2 200 24 48 248

have something like

ID Item Type Value
1 1 Price 100
2 1 VAT% 24
3 1 VATAmount 24
4 1 Sum 124
5 2 Price 200
6 2 VAT% 48
7 2 VATAmount 48
8 2 Sum 248

(you would of course not have Type as a string like this, but rather some
kind of integer linked to another table with the names)

Just a thought, I know nothing about your particular case,
Set