Fast way to get all item numbers with a specific format?

[jgkoehn]

Greetings,
Is there a fast way to get all items with a specific format and put that item number in an array.
At present I am going 1 by 1 through the items and would like to see if there is a faster way.

[Sergey Tkachenko]

This is the only way, to check all items.
But I think it is very fast, unless you need to perform it multiple times regularly.