0 - 2 of 2 tags for numbers

Hello everyone,

I need some help figuring out how to drop the last four digits of a 9 digit zip code. If I have a list of subscribers with a couple hundred thousand that have zip codes withe the following format...."27751-9099". Is there anyway that I can remove the last four digits so that we can compare zip codes based on a 5 digit basis?

I have a column that has both numbers and texts in the fields.
xyz 120 abc lmnop
xy 120
?/ 567 abc
.... 233

As you can see the fields can have numbers, texts, special chacters, null values, etc. If there is a no numbers in a field I want to return null for that.