Match query string within indexed field?

Hi,

My requirement is to give a match whenever a string is found within the
indexed data of a field irrespective of where it is found.

For example, if I have a field which is indexed with the data "abc". Now any
of the following query string must give a match: xyzabc,xyabc, abcxyz ..

I am using *solr.KeywordTokenizerFactory* as the tokenizer class and
*solr.LowerCaseFilterFactory* filter as index time in *schema.xml*.

Could anyone help me out as to how I can achieve the functionality.

Thanks in advance.