Jamesbond... that is exactly what I was hoping someone here would say, since I have a tendency to be skeptical of negative responses from companies who would gain financially by such response.
My certificate starts with: -----BEGIN CERTIFICATE REQUEST-----
The host with whom this domain formerly resided was kind enough to send me 2 files, one of which they say is the key.
One starts with: -----BEGIN RSA PRIVATE KEY-----
The other starts with: -----BEGIN CERTIFICATE REQUEST----- (WebHost Manager stated I don't need this one).
I tried installing my certificate on my main server, which hosts the domain in question as a reseller account. When that didn't work, I went into WHM for the domain in question and tried to install the certificate there.
On the worst case scenario, I got this result:
Attempting to verify your certificate.....
Modulus mismatch, key file does not match certificate. Please use the
correct key file
-----------
Key Modulus
Modulus=C0414BD181B35B725DEDF0E15E340AE7F443EA497710F12F91F3B297A8A05870F22E
25B731D45271D358DD0C2807C9C42CF4913E0C035C96DE75D60A42EDE7F967E80325AC3CC360
F1E646341B4EA4B7302C0CE1CA91DA59694967A1C4F7B5A02681E26B55060F7067FB425A078A
C3C62E643BA193DF932E47872CBCDE7B067D
Crt Modulus
Modulus=C8CE602774F93AB3B7F982042E28181D2A8D85B0C43F74941CDFE93AF006865A99BE
4D5108B41B130AFF00F6D
-----------
On the best case scenario, WHM stated something to the effect of: &key does not match domain IP address&.
GeoTrust won't answer my question, passes the buck to their reseller, who's tech support says they are not obligated to answer the question either.
I feel so unloved ...
