Excel - Replace matching column values based on another column set
<p>I am wondering if there is a way to replace values in one column to new values from another column set. Like an auto search and replace confined to a column where the search/replace data is dictated by the column set from another excel file. Specifically here's the situation.</p>

<p>In one column I have old user IDs like so, which can't be sorted because it's a CSV for importing into a website and it has duplicates which each row represent new forum threads &amp; replies etc:</p>

<pre><code>7766
7779
7781
7782
7791
7792
</code></pre>

<p>I need to replace these values with the new correct values.
I have two other columns in another excel file where I have the old member ID numbers next to it's corresponding new member ID number in ascending order, like this:</p>

<pre><code>7066    637
7067    638
7068    639
7069    640
7070    641
7071    642
7072    643
</code></pre>

<p>The topic/thread file I manually used the search and replace function for all members which took a very long time... I'm wondering if there's an automated way to do this for the reply file? which has substantially more data rows.
Thank you</p>