Foreign language chars as map keys

I have a Groovy list that holds the unicode representation of select
foreign language characters, something like this simplified version:

def myList = ['*\u00E4*','\u00D6','\u00F8']

I have built myself a Groovy map that is the crosstabulation of characters
by count in an incoming document, so my map looks something like this:

crossTab = ["a" : "16736", "b" : "192", " * ä  *" : "18"]

The foreign language characters in this map that are in the set of keys
often have extra whitespace around them, and for certain languages there is
a weird "right to left" thing going on that I don't quite fully understand.

My objective: iterate through my list, return true if the element from the
list is found as a key in the map, and return the count - the map value for
that key - if the key is found. My problem: my lookup is failing to return
any hits right now. I know that some of these foreign language characters
are in my data. I suspect my lookup is failing because the keys are not
clean representations of the foreign language characters.

How do I modify my keys using Groovy to trim them of leading and trailing
whitespace?

Since my element from my list is expressed as unicode, how would I convert
the trimmed key representation to unicode using Groovy?

Thank you in advance for any help.