Change Link Source

I want a macro to change linksource.

I have two excel Workbooks (say Wkb1 & Wkb2) linked to a different
application software. I have made another workbbok (say "Main Wkb") which
has the values used in Wkb 1 & 2. Wkb1 & Wkb2 are externally linked to Main
Wkb. I have presently all three in same folder.

Let current directory is "C:\A" for all the workbooks. Now, application
saves Wkb1 & Wkb2 in "C:\B". I will paste "Main Wkb" in "C:\B" manually.
Then, I want a macro which should change the link source of "C:\A\Wkb1" &
"C:\Wkb2" from "C:\A\Main Wkb" to "C:\B\Main Wkb"

Please HELP!!!!!!