how to compare a varaible that contain a list of strings

[#1]

hi

i have a problem to compare a veriable that contain a list of strings .

i create a varaible "corp_name" like this : getfieldselections(dim_corp.corp_name,',',10).

it means that all corp_names that the user choose will save here as a list of strings (separate by comma).

my code is this:

=if(isnull(Corp_Yehidat_Finance),

                    count (DISTINCT if (num(FACT_WINS_HT_Begin_Date)<=$(SelectionDateNew)

                                          and (num(FACT_WINS_HT_Begin_Date)+num(FACT_WINS_HT_OPN_over14))> $(SelectionDateNew)

                                    and  FACT_WINS_HT_OPN_over14 >14 ,FACT_WINS_HT_Mezahhe_Mismach,null())),

                         count (DISTINCT if (num(FACT_WINS_HT_Begin_Date)<=$(SelectionDateNew)

                                          and (num(FACT_WINS_HT_Begin_Date)+num(FACT_WINS_HT_OPN_over14))> $(SelectionDateNew)

                                    and  FACT_WINS_HT_OPN_over14 >14

                                    and (FACT_WINS_HT_CORP_NAME like Corp_Yehidat_Finance) ,FACT_WINS_HT_Mezahhe_Mismach,null())) )

FACT_WINS_HT_CORP_NAME is the fiels i want to check .

when the user does not choose a corp_name i bring back all "FACT_WINS_HT_Mezahhe_Mismach" under the conditions.

else i need to bring back just the chosen one's.

when my varible contains more then 1 value it doesnt work...

maybe there is a function that know how to compare this?

tnx

elad