In order to keep selected CSS styles in converted HTML you can replace style=”…” attributes to some unique placeholder string like ###XXX###. Later just remove all style attributes from HTML with regular expression find/replace like this: \s+style=”[^<>”]*” and replace ###XXX### back to style=”…” attribute. Please import and test this template in Word Cleaner, it demos more advanced find/replace entries that show how to keep alignment styles only in converted HTML.

Find/replace align css