alias for numerical or text input vs. keymap

I'm wondering if I am going about this the right way:

In an editor I have a child cell collection.
The type of the children is an interface.
Several concepts implement that interface.
Most of them start with a special character.
I use that character as an alias so the cell switches to the correct concept when I enter that character in the cell.
One of those sub-concept editors starts with a string property however and another with a number property.
I can set multiple aliases to have the cell assume the correct editor - however then the input misses the starting character.

So I resorted to using a keymap to catch 0-9 and a-z and replacing the node with the appropriate one.
That seems to work so far but before I go down this route further:

is there some simpler way to have a cell that assumes the correct concept and doesn't drop characters ?
Thanks