Hi Warren,
I think what you are suggesting is basically a limited Concgrams kind of feature. This *would* be possible in AntConc if the context search accepted wildcards. Then, you would be able to specify 'spend*' as the wildcard and search for 'time'. This would give you the results you want. But, AntConc does not allow this yet. In fact, someone else asked for the same feature. Others have asked for a full-blown Concgrams feature.
Let me look at the code and see how easy it would be to implement. I'll report back here what I find.
Regards,
Laurence.