Picking Number String out of Text String

Hi I have a text field which has entries of variable length of the form:

"house:app.apx&resultid=1234,clientip"

or

"tost:app.apx&resultid=123,clientip"

or

"airplane:app.apx&resultid=123489,clientip"

I'm trying to pick out the numbers between resultid='...',clientip no matter what the rest of the string looks like. So in this example it would be the numbers:

1234 123 12389

the part of the string of the form resultid='...',clientip always stays the same except the length of the number can vary.

Any tips greatly appreciated.