if conditions in Custom BB Code?

[Tim Skellett]

I tried setting an if condition in a Custom BB Code, but the if condition was not parsed at all, and in fact simply sent on to the end-user browser as if it was unrecognised code, i.e., the if condition was typed out in the source text of the page, and only the parameter was shown in the page, like so:

Shown on page: ... yada ....
Shown in "View Source" of browser window: <if condition="abcde">....yada</if>

So my question is: is there any way I can build an if condition into a Custom BB Code?

I also tried out building an if condition using Replacements (two, one for the <if=... part and one for the </if part), but I ran into exactly the same problem as with the Custom BB Code. The if condition was not parsed and was printed out as before.

Many thanks in advance for all help.