Not integer

I need to match any string that contains at least one non digit at any place:

should match:
10321foo12bar
foo1bar1123
foobar

shouldn't match:
1
10
2023

I successfully matched a string that contains at least one non digit but it doesn't work for following example:

320.3t foo bar (blah)
while it matches:
3203t foo bar (blah)

here is my regex:


What am I doing wrong?

P.S.
This is just a part of my whole regex, it's basically one backreference so I can't use ^...$, can I?

Normally I'd say

but if it's part of a regex then you may need something more like

but then I wonder, what exactly does "just a part" mean?