Regular expression can be used to extract numbers from the text strings. Since the numbers can potentially be in any position and even combined with text, I'll suggest using the '(\d+)' matching pattern. This will match and extract any digit of any length at any position.
In the attached sample workbook, I have created a calculated field [Numbers]
The numbers will be initially be extracted as strings. INT() will convert them back to integers.
Hope this helps.
I didn't refresh my browser before posting. Shin has suggested similar solution also.