I need to build a string for each "checked" multiple choice

Hi,

Hope someone can help!

I have a multiple choice field which has 5 options (at the moment, this may change).

I have another field which is a numerical value, and for each of the enabled multiple choice options, I need to build a HTML string with the value of the numerical field, followed by the name of the chosen option..  

eg: 
Base Price = £8
Multiple Choices:  Paper, Card, Metal, Canvas, Glass, Cotton

If Paper and Canvas were selected, then the HTML string would need to be :

Subtotal: £8+ Paper : £8+ Canvas : £8

I'm sure its really simple... just need to know how to loop through a multiple choice array with JUST the chosen items, and building a string on each occurrence of a chosen option..

Thanks in advance,

J.