Summing numeric parts of alphanumeric values

Hi,

I am wondering if you can sum the numeric parts of a range of cells containing alphanumeric values. Here is an example:

values to sum: 500, a20, ab30
expected results: 500 + 20 + 30 = 550.

In this project, the number of values to sum is large and I do not wish to use long formulas to extract the numeric part of each cell within the range. I am also forbidden to use up extra cells as an intermediate working out. Can you help?

Cheers guys.