Do not ever run an E4 film through E6 or C41. It will ruin the film and the process chemistry. The emulsion is too soft to survive and will float off in gobs and ruin the First Developer and any films going through with or after it.

If you wish to use it, use a prehardener, a neutralizer and a wash before the C-41 color developer. Even then, the C-41 process may be too "hot" for an E4 film. You may have to play with the time.