passing parameter in function module

hi friends,

I have created one function module in which i need to pass PO/SO number from standard EKKO/VBAK tables through the select option parameter S_POSONO. Inside the function module I have a select query which fetches the records from a Z-table which has a field called 'REFERENCE' which is 16-char long. Hence the length mismatches with PO/SO no which is 10-char long. the first 10-char from 'REFERENCE' is PO/SO number, next 3-char is line-item num, and the last three char is schedule item num. It is required to match only first 10-char with the parameter passed i.e, S_POSONO and display only those datas.

The function module is as follows.....

Function :

CALL FUNCTION 'YFIIN_RETRIEVE_SOURCE_DATA'

EXPORTING

LT_RANGE_BUKRS = S_BUKRS[]

LT_RANGE_DOCNO = S_POSONO[]

LT_RANGE_DOCDATE = S_DATUM[]

LT_RANGE_CURRENCY = S_FCURR[]

TABLES

IT_TEMEXPOSU = LT_TEMEXPOSU

EXCEPTIONS

INVALID_SELECTION = 1

OTHERS = 2.

IF SY-SUBRC <> 0.

• MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO

• WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.

ENDIF.

Source code inside function module:

SELECT * FROM ZFIGL_TEMEXPOSU INTO TABLE IT_TEMEXPOSU

WHERE COMPANY_CODE IN LT_RANGE_BUKRS

AND currency in LT_RANGE_CURRENCY

and REFERENCE in LT_RANGE_DOCNO

and doc_date in LT_RANGE_docdate.

IF SY-SUBRC = 0.

SELECT COMPANY_CODE ATTRIBUTE_01 REFERENCE CREATION_DATE FOREIGN_CURR

FROM TEMT_RAWEXPOS APPENDING CORRESPONDING FIELDS OF

TABLE IT_TEMEXPOSU WHERE COMPANY_CODE IN LT_RANGE_BUKRS

AND REFERENCE in LT_RANGE_DOCNO

AND CREATION_DATE IN LT_RANGE_DOCDATE

AND FOREIGN_CURR IN LT_RANGE_CURRENCY.

ENDIF.

Import Parameter of Function Modules :

LT_RANGE_BUKRS - type - BUKRS

LT_RANGE_DOCNO - type - EBELN

LT_RANGE_DOCDATE - type - DOKDATS

LT_RANGE_CURRENCY - type - WAERS

please help me to solve this problem..