ALV report requirement ?

Hello,

I have kept a button in the application tool bar and declared the user command its all working fine.

What i want to communicate is like when i select a particular material number from the list of material numbers displayed by ALV, select particular material number and click the button kept in application tool bar by which the document related to that material number has to display automatically allthe documents are stored in the desktop.

My folder name is "NEW" and one of my document name is ONE.doc. For opening the document automatically i have the idea of concatenateing the path but not getting the exact syntax my code is..

CALL METHOD cl_gui_frontend_services=>file_open_dialog

CHANGING

file_table = lt_filetab

rc = v_rc

EXCEPTIONS

file_open_dialog_failed = 1

cntl_error = 2

error_no_gui = 3

not_supported_by_gui = 4

OTHERS = 5.

READ TABLE lt_filetab INTO ls_filetab INDEX 1.

IF sy-subrc = 0.

v_file = ls_filetab-filename.

CALL METHOD cl_gui_frontend_services=>execute

EXPORTING

document = Concatenate 'C:\Documents and Settings\New\' and 'MATNR'.

ENDIF.

but this code is not working can anyone suggest me where to concatenate the path and document name.

Useful answers will be appricated.

Thks