remote search help for webdynpro screen field

Hello,

I have a requirement as follows :

1) There are two fields on a webdynpro screen - A and B

2) For field B, i need a search help, the values for which are stored in a remote system.

3) The name (RFC destination) for the remote system is stored in a table, against the value of the field A. Means, this table has the value of field A on the screen, and along with it, there is the name of the remote system.

Now the requirement is that when i press F4 for the field B, i need to pick up the value of field A (on pressing F4 only), use this value to get the remote system name from the table. Then use this remote system name to call an RFC which returns a table of values which are to be shown on the search help screen.

Alternatively, is it possible that i can create the search help in the remote system and then call it from the screen field B?

Could anyone please give any pointers? Is this a possibility using webdynpro ABAP?

regards,

Priyank