Controlling Hero's Spells

[Progesterone]

Dear all,
I wish to ensure that in order to learn a particular level for a certain spell, the hero must reach specific levels first.
Much clearer with this example: To learn Level 1 of Spell X, hero must be at least level 1; to learn level 2 of Spell X, hero must be at least level 3; L3 of Spell->Hero min L6; L4 of Spell-->Hero min L10; L5 of Spell-->Hero min L14
Ie, I understand that there is a part under spell editor to specify the "level intervals", but my situtation cannot be solved by that as the "intervals between the minimum levels required of the hero" is not the same across different levels of the spell.
Can someone please help me ? Thanks !

 

[KaerfNomekop]

You might specify unit requirements for each level of the ability, with the unit's names as Level 1, Level 3 and Level 6 etc. Though I'm not sure if this method works with different requirements for different levels.

 

[Progesterone]

Kaerf, thanks for the reply. Can you elaborate on that ? (ie, which exact field do I change ?) Thanks !

 

[Inflicted]

It's under the individual abilitiy. In the Object Editor.

 

[KaerfNomekop]

The Techtree - Requirements field. I think it goes by level, i.e. Level 1 requires the first item in the list, Level 2 requires the second item and so on. That is, if it actually works.