regex – How can I replace all spaces between two characters with `_` in MS Word?

How can I replace all spaces between two characters with _ in MS Word?

Following removes all characters between two < and > when using wildcard feature in MS Word. But I want to replace only empty spaces with _.

For example:

• Input String: This is a test only. Just for only
• Final Output: This is a kind_of_a test only. Just for the_testing_purpose only

Wildcard in Find box:
\<(*{1,})\>

Remarks: This is a long document. Replacement needs to be done only on all the contents enclosed by < and >. No macros, no manual find and replace. In the Find and Replace dialog box of MS WORD, after entering Find and Replace values and choosing Wildcard option, the Replace All button should do the required replacement.