League Manager does not allow a "regular" player in one division to sub in another division.
If you ask LM for a sub, it will go to the sub list at the bottom of the page...which will be the same for every division in a league.

If you have a player who wants to sub in a different division, here a 'work around'...

1. First add a sub(s) called "Regular Player" to the sub list. You can use this sub when a regular player plays as a sub in another division.
On the main list, scroll to the bottom of the list. (where subs start) Then add a sub..first name "Player", last name "Regular"

2. Highlight the player that DID NOT show. Click the SUBSTITUTE button, and make "Regular Player" his/her substitute.

3. On the main list, scroll to the bottom and double click the "Regular Player" sub to view the player info form. In the HCP column give "Regular Player" the correct handicap.
Then click the LOCK HANDICAP check box to lock the handicap at this value.

4. Pull up the scorecard and enter card as normal.

If you also want the score..shot as a sub to affect the regular player's handicap....

1. Double-click the golfer to view his player info form.

2. Type the score in where it says "Add Extra score".

This score will be included in calculating the golfer's handicap.