PLUGIN FOR CALCULATED PRICE TO WP E-COMMERCE CART

I need a plugin like the existing one : CALCULATED FIELDS, but with some more functionality I want to get as result an amount depending of various fields which i can define. Lets give an example: Asume that i have a wp e-commerce product with a specific id and a STANDARD price per unit (unit is piece - integer value) The product may have one or more group of variations and a unit price according to variation (e.g. var1=color, var2=material with color1=+c1 euro, color2=-c2 euro...... and mat1=+m1 euro mat2=+m2 euro .... etc Note that the sign has a role. +c1 means that the c1... value have to be added to the standard price. -c1 has to be subtracted. Also in some cases i need the variation price to be a percentage of Standard price. Thus it could be : +c1 or -c1 or +c1%. Explaining the last one: if the STANDARD price is 80 and i have a variation with +25% then the +25% means that i have to ADD (+) 0.25*80 to the standard price (result 100). If no % symbol, then i have to ADD 25 euros, result 105 ) (+ / -) c1,c2,m1,m2 are value of euros ADDED or SUBTRACTED to the standard price. And if followed by % then the percentage has to be ADDED or SUBTRACTED. When i click the product from the grid i' m getting in it's detailed form. In this form i want to put the plugin (via shortcode) ***Firstly**** the customer must choose from variations (if exist one or more). So we have the price according to variations ***Secondly**** The product in it's detailed form, may have some fields set by me (may have or not. If i put the plugin with the sortcode in the detail form of the product then there are the fields). Field_1 (horizontal dimension - input by customer) Field_2 (vertical dimension - input by customer) field_3 (optionA selection with case 1,2,3....) field_4 (optionB with case 1,2,3...) field_from_db: a value got from database depended from the product. i want to name which field i select and may be is more than one. Field5 : image collection inside frame to select (somethin like a combo box but for images. A image list with paginator and previous / next controls rising as pop up window like joomla extensions) Amount = ((Field_1+opA)*(Field_2+opA)+field_from_db)*(PRICE_AFTER_VARIATIONS+opB) >>>> this is a customizable final field as result. opA and opB are values depending of what i selected from optionA and optionB. The Amount which is the result, and the field5 i want to be passed in the cart, after the customer press the BUY button. The Amount is a field to be passed as the price in the cart. But other fields may be have to be passed. Such fields is the Field5 (image) and maybe a text field or numeric one. It's good to predict a flag PASS_THE_FIELD_TO_CART (true / false) so i can adjust if a field is to be passed. With the same plugin, various cases of forms may be constructed. They will have different shortcode so i can put in different products different forms of the same plugin, providing the proper shortcode. That's the chalenge.