How to use specific mathematic symbols in fields?

Hello,

inside a Paradox 8 re****t I've created new calculated field, which shall 
contain following formula:

0.8575 * sqrt((ansicode(string([STREETS.PQ1], 1, 1)) - ansicode("T"))^2) +

(value(string([STREETS.PQ1], 2, 2)) - value("06")) ^2 )

The story behind is: there exists a table (STREETS) with field "PQ1" (e.g.

for entries: T06, R10, ...). The field (type "A") has a length of 3 
characters. Now I want to convert the text string into 2 values (see
formula 
above).

But Paradox doesn't accept the symbol ^ and neither "value". What can I
use 
instead?

Thanks in advance.

Frank