[TYPO3-Solr] Problem formating data from SOLR_RELATION

[Tim Werdin]

This is a split up from a previous ticket of mine.

I have a relation to a table with leasing data and I get back the 
leasing rate back but it isn't formated like I need it.
I have tried _stringS and _floatS. As a string I get back e.g. 
20000.0000 which is exactly what is in the database. When I use float I 
get back 20000.0
But I need 20.000,00 € with stdWrap numberFormat and noTrimWrap this 
wouldn't be any problem but unfortunatelly SOLR_RELATION doesn't 
support stdWrap so how could I format my data?

plugin.tx_solr.index.queue.wv_stx3.fields {
  leasingrate_stringS = SOLR_RELATION
  leasingrate_stringS {
    localField = leasing
  }
}

Kind regards
Tim