url rewrite mybb to vbulletin

[Domiav]

Hello guys;
i was looking for a url rewrite rule to rewrite the old urls based on mybb to the newest one that vbulleting give me.
the url on mybb are:
http://www.website.com/forum/showthread.php?pid=44406#pid44406
vbulletin:
http://www.website.com/forum/showthread.php/2123-discussion-name?p=44046#post44046

i tried with:
http://www.website.com/forum/showthread.php/p=44406#post44406 but doesn't work, seems that i miss the "2123".
Any idea on how to write a rule to make the full url? thank you!

[Mooff]

Just check the links here on vbulletin.org
This thread:

https://vborg.vbsupport.ru/showthread.php?t=273035

Your post:

https://vborg.vbsupport.ru/showthread.php?p=2262756#2262756

this forum:

https://vborg.vbsupport.ru/forumdisplay.php?f=251

[Domiav]

sry i didn't understand you; as far as i can see vbullent impex system doesn't keep my thread ids that are on mybb:)
i've however made some improvemente and i've found a background on my urls:
mybb url are like:
www.old.com/forum/showthread.php?tid=number

and vbulletin are:
www.new.com/forum/showthread.php/samenumberonmybb-121
Now the problem is:
How i can suctract 121 on the mod_rewrite using .htaccess?
thanks.