Convertion VarChar Error

Ive got a small problem at the moment

I have ran a query that has been used for a while now and have recieved this error

Server: Msg 245, Level 16, State 1, Line 3
Syntax error converting the varchar value 'N' to a column of data type int.

Ive searched the data and the only value of N that i can find is currently sitting in a field where the field type is varchar

is there a workaround for this, Ive tried running a case statement to set the N to 0 and also tried casting

Cheers in advance
Dave...the only value of N that i can find is currently sitting in a field where the field type is varcharso why is it trying to convert this value to an integer?

i have no idea, because i can't see your query from here

:)|||rudy man i thought you were psychic

-- 5302 MH consultant OP first attendances

SELECT CdsType,
NHSTrust,
AttendedOrDNACode, --N apears here varchar(1) column
FirstAttendanceCode,
SpecialtyCode,
Specialty,
PCG,
PurchCode,
datepart (year, ActivityDate) as yearAct,
datepart (month, ActivityDate) as monthAct

FROM dbo.VIEW_Outpatient2000_Analysis

WHERE PurchCode like '5KW%'
--pcg like 'Chelt%'
and NHSTrust not like 'Glou%'
and FirstAttendanceCode = 1
and AttendedOrDNACode in ('5', '6', '1','N')
and SpecialtyCode between '710' and '715'
and ((datepart (year, ActivityDate) = 2004
and datepart (month, ActivityDate) > 03)
or (datepart (year, ActivityDate) = 2005
and datepart (month, ActivityDate) < 04))

So im pretty much confused, cant see anything there that would cause a problem|||the 'N' may not necessarily be where you think it is

FirstAttendanceCode = 1|||Ah Blind as a Bat i am
Cheers rudy