Your post/inquiry doesn't provide enough information to understand the problem. Perhaps you could tell us what product your using, what the problem is and what your trying to do...
[if you’re not clear with your question(s), the answer(s) can be just as skewed]
While this is NOT a solution; it's more of a workaround to what your saying/requesting...
My suggestion, research AUTOHOTKEY...
It could open Windows Live Writer and send keystrokes to select the BLOG you want to use.
Like this:
run, [path to Windows Live Writer]\WindowsLiveWriter.exe ;;-select blog menu send, [ALTDOWN]B[ALTUP]
;;-- select blog send, [down][down][down][enter] exitapp
OR
Define a hot key in Windows Live Writer to switch to the blog you want quickly... my example shows how F1 and F2 could be set for two different blogs and switch by pressing a single key.
F1:: ;;--WILD Ones Blog -- Comment send, [ALTDOWN]B[ALTUP]
;;-- select blog send, [down][down][down][enter] return
F2:: ;;--WILD Twos Blog send, [ALTDOWN]B[ALTUP]
;;-- select blog send, [down][down][down][down][enter] return