Php format numbers in a string with regexp

Question

I need help with writing a regular expression in PHP. I am not friend enough to get it right. I need to find all integers in a string and format them as follows:

Answer 1

From your examples looks like you are multiplying the number with 1000 and prefixing them with 0's to make a total of 6 digits. If that is true you can just do:

sprintf("%06d",$n*1000);