Searching a substring: Is it possible to check whether a given string is a substring?
Use the "search=" option of the "Set" command. Example:

Set V[title] "xhaskdjfhsdjkfjdsasdf234lsjksld2l34 oqsdfsafaa"

Set V[x] "&V[title]" search="ksl"

if Q[ok]

 Message "Substring found"

endif